In an attempt to seal the Gates of Hell, hunter Sam Winchester begins performing the Trials of God. Performing the trials starts causing Sam increasing damage until the Third Trial nearly kills him. At the same time as Sam performs the Third Trial, the Scribe of God Metatron orchestrates the Fall of the Angels, resulting in every angel falling to Earth and becoming trapped.
In a desperate attempt to save his brother from the fatal damage the Trials did to him, Dean Winchester calls upon any angel to heal Sam. The angel Gadreel, disguising himself as the deceased angel Ezekiel, attempts to heal Sam but is ultimately too weak and Sam too damaged for him to do so. With Sam preparing to go with Death, Dean agrees to allow Gadreel to possess Sam and heal his brother from the inside. Dean is able to trick Sam into saying "yes" to Gadreel who wipes Sam's memory of his near-death experience so that he won't know that Gadreel is inside of him and potentially expel the angel, something that would prove fatal to Sam in his weakened condition.
Months after the Fall, Gadreel is approached by Metatron and offered a chance to gain redemption for his past failures by becoming Metatron's second in command. Gadreel ultimately accepts Metatron's offer and is assigned to assassinate the Prophet Kevin Tran. At the same time, Castiel learns from Malachi that Ezekiel is dead and warns Dean who attempts to suppress Gadreel so that Sam can expel the rogue angel. Gadreel is able to alter the sigil so that it fails to work, kills Kevin and escapes in Sam's body with the angel and demon tablets.
After Gadreel kills Kevin Tran, Metatron gives him the name of Thaddeus as his next target. Thaddeus is an angel who guarded Gadreel and his friend Abner while they were locked in Heaven's dungeon and brutally tortured the both of them. Following the Fall of the Angels, Thaddeus has taken the pop star Corey as his vessel.
Still possessing Sam Winchester, Gadreel waits for Thaddeus in Corey's dressing room. Though surprised to see Gadreel, Thaddeus keeps Corey's assistant Margey or security from intervening. Thaddeus explains that after getting kicked out of Heaven, he decided to enjoy life on Earth by being a pop star. While Thaddeus greets Gadreel warmly, Gadreel is less than pleased to see him due to Thaddeus' torture of him. Thaddeus insists that he was just doing his job with Gadreel, but admits that he had fun torturing Abner. Thaddeus realizes that Gadreel is after revenge and offers to kick Gadreel's ass again "for old time's sake." However, when he opens Corey's guitar case to get his angel blade, Thaddeus finds it gone. Turning around, Thaddeus discovers Gadreel holding his angel blade. Thaddeus tries to apologize, but Gadreel stabs him in the chest with his own angel blade, killing Thaddeus.
After being called by Dean, the angel Castiel arrives at the Men of Letters bunker to find Dean arming himself to go after Gadreel for revenge. Castiel realizes that something is wrong from the wrecked state of the room and Dean explains everything that has happened to him. Dean states his intention to destroy Gadreel for everything that he has done, but Castiel reminds Dean that "you kill an angel its vessel dies too," meaning that killing Gadreel would also kill Sam. While Dean acknowledges this, he feels that he doesn't have another choice.
Castiel admits that Dean was stupid in his actions but he was stupid for the right reason. Castiel tells Dean that Sam is strong and if Sam knows that an angel is possessing him, he can cast the angel out. "Maybe," Dean acknowledges, "but as far as I know, he's in the dark. I don't know how we clue him in." Castiel remembers that before Samandriel died, he had told Castiel that the demons were able to dig into his mind and access his coding. Castiel suggests that they do the same exact thing to bypass the angel and talk directly to Sam. While Castiel is not sure if it will work, both he and Dean think that its worth a try.
In order to learn how to hack Gadreel, Dean and Castiel approach Crowley who is locked in the bunker's dungeon. Dean offers that in exchange for Crowley telling them how to hack an angel, he will give Crowley fresh human blood to feed Crowley's blood addiction. Crowley refuses the offer however. Instead, Crowley asks for a massage from Kevin, only to be informed that Kevin is dead. Crowley expresses seemingly genuine sorrow over Kevin's death and tells Dean that he had seen Kevin's death coming and warned Kevin to run from the Winchesters. Crowley points out that "people in your general vicinity don't have much in the way of a lifespan."
Crowley admits that he can't teach them how to "crack open an angel", calling it more of an art than a science. However, Crowley offers to do it for them in exchange for a "field trip" and some fresh air which he is willing to do chained up. Dean refuses, but begins to relent when Crowley points out that if he needs Crowley's help, he must not have any other options. Castiel is reluctant to go along with the plan, pointing out that even with the chains on "its Crowley, he can always do something." Crowley suggests bringing in Sam to act as a tie-breaker before realizing from Dean and Castiel's silence that Sam's the one in trouble and needs to be saved. Dean finally agrees to the deal, stating that they will leave "as soon as I can scrounge up a ride." To Dean's surprise, Castiel admits that he has a vehicle that "stopped a few miles from here, inexplicably."
After releasing Crowley from the dungeon's devil's trap, the three make their way down the street to Castiel's vehicle, draping Crowley's jacket over his hands to hide the Supernatural Handcuffs binding Crowley. As they walk past a house, they are observed by a woman and her dog, the woman in reality being possessed by a demon loyal to Abaddon. Reaching Castiel's Pimpmobile, Dean quickly determines that the car is just out of gas and fills the tank up using a gas can that he has brought with him as Castiel and Crowley bicker. After getting the car running again, Dean consigns the angel and demon to the back seat and they drive off together to find and save Sam.
At a bar, Gadreel brings a pleased Metatron the angel and demon tablets. Gadreel is surprised to find that the bartender is his old vessel, something that Metatron acknowledges the strangeness of, comparing seeing an old vessel to "looking in a funhouse mirror." Metatron asks about the tasks that he gave Gadreel who calls killing Thaddeus "easy" as Thaddeus had it coming. Metatron is well aware of Gadreel's history with Thaddeus and states that he sent Gadreel after him for that very reason. "Consider it your signing bonus."
When asked about killing Kevin, Gadreel admits that it was "less easy". Metatron calls Kevin a threat and tells Gadreel that he has "flipped a switch upstairs" so that there will be no more Prophets now that Kevin is dead. Metatron asks about what Gadreel did with Dean and Gadreel points out that Metatron never gave him Dean's name as a target. Metatron is annoyed that Gadreel didn't take the initiative to kill Dean on his own and states that they are writing their own epic story "and sometimes you have to kill your darlings." Metatron earns a glare from Gadreel when he points out that Gadreel has done worse before and changes the subject.
Metatron then gives Gadreel the name of Alexander Sarver as his next target. Gadreel is upset that he has to keep killing and questions Metatron on how many more people he will have to kill. "It is not your place to ask questions, it is your place to obey. You wanna be my second in command, prove your ready, prove your loyal. Or don't. Walk away, go back to being Gadreel the traitor. The sap. Heaven's longest running joke."
The next day, Crowley takes a skeptical Dean and Castiel to Waldroff Financial to meet with a source of his that can help them track down Sam. Crowley explains that the company is actually a front for an NSA listening post used by the government to spy on everything. "So I planted one of my best and let her go to work." When asked about if he was looking for terrorists by Castiel, Crowley states that he was "looking for marks." A security guard then approaches them and states that Crowley's contact will see Crowley and only Crowley. Castiel promises to listen in on everything Crowley says, but finds out that the room Crowley is in has angel warding, preventing Castiel's powers from working.
Crowley meets with Cecily in her office and Cecily recognizes Dean and Castiel as the ones who were with him. Cecily expresses an attraction to Castiel and fills Crowley in on Castiel losing his grace and then stealing the grace of another angel to get his powers back "minus the broken wings." Cecily explains that she knows what's going on with the angels as she tuned one of the NSA listening satellites into "angel radio."
Crowley asks about Hell and is informed that no one is doing their job in Hell. Cecily also tells him that Abaddon isn't the boss and has "a few of the more aggro types on her side, but most are just waiting to see who takes the belt: you or her." Crowley realizes that the demons are still afraid of him, but Cecily suggests that its only because the demons don't know that Crowley is in handcuffs. Crowley tries to get Cecily to remove the Supernatural Handcuffs, but she is unable to do so without the key.
Crowley asks Cecily to track down the Impala for him, something that she states is easy for her to do. Crowley is pleased to find out that someone is still loyal to him, but Cecily's reaction makes it clear that she isn't. Crowley realizes that Cecily is playing both sides, something that she confirms by asking him "wouldn't you?" Shortly afterwards, Crowley emerges from Cecily's office with the news that the Impala ran a red light in Somerset, Pennsylvania ten minutes before. Dean, Crowley and Castiel depart for Somerset to find Sam and Gadreel.
In Somerset, Gadreel arrives at the home of Alexander Sarver and is shocked to find out that Sarver is actually the vessel for his old friend Abner. Abner greets Gadreel warmly and reveals that he has a family, asking that Gadreel return in a few hours once his wife and daughter have gone to a movie so that they can catch up. Visibly conflicted to find out that Metatron has sent him after his one friend, Gadreel agrees to Abner's request.
That night, Gadreel and Abner talk in Abner's living room. Gadreel is surprised to find out that Abner has a job as well as a family. Abner describes his customer service job as similar to answering prayers "but they pay you for it." Gadreel realizes that his old friend has changed. "I was a crappy angel. I was petulant. I deserted my post. I spent seven hundred years in Heaven's lockup. I... No, doesn't matter. We're a long way from Thaddeus now."
Gadreel tells Abner that he has killed Thaddeus and gotten their revenge, but Abner wishes Gadreel hadn't done so, even though Thaddeus tortured Abner most of all. While Abner remembers what Thaddeus did to him, he also remembers Gadreel being there to put him back together. Abner sees the Fall as their second chance. "We can forget our old hates, who we were." While Gadreel believes it not to be so simple, Abner thinks it is, telling Gadreel that he's happy with his new life as Alexander Sarver. Gadreel asks about Abner's vessel and is told that "he was an abusive ass" and Abner loves his family and they love him back. "I'm not a wise man Gadreel. But I know this: the key to happiness, its getting the one thing you want most and never letting it go." Steeling himself, Gadreel asks Abner what to do if there is a price for getting that happiness. "There's always a price, but its worth paying," states Abner. With a sigh, Gadreel gives Abner a considering look.
A short time later, Dean and Castiel make their way to Abner's house past the Impala still parked out front. Entering the house alone, Dean finds that Gadreel has slit Abner's throat. Following the sound of running water, Dean finds Gadreel cleaning Abner's blood off of his hands at the kitchen sink. Sensing Dean behind him, Gadreel turns around, stating that Dean should not have come. Armed with an angel blade, Dean reminds Gadreel that Gadreel had murdered his friend and taken his brother, both of which are things that Dean couldn't allow to stand. Gadreel reminds Dean that he did allow him to live, but Dean calls it a mistake and charges Gadreel with his angel blade. Gadreel telekinetically flings Dean into a bookshelf, knocking him out. Before Gadreel can do any more, Castiel enters the room. As Gadreel turns to face him, Castiel knocks the rogue angel unconscious with a single punch.
At Waldroff Financial, Cecily meets with Abaddon in her office. Cecily informs Abaddon that Crowley has gone to Somerset, Pennsylvania with Dean Winchester and the angel Castiel, causing Abaddon to question the source of Cecily's knowledge. Cecily explains that the group was chasing an Impala and she helped Crowley track it. Abaddon is less than pleased to learn that Cecily has helped Crowley and Cecily nervously explains that she is playing both sides until Abaddon wins. "Smart, right?" Cecily questions. Abaddon backs Cecily's chair into a corner before killing the demon with an angel blade. "No. Sort of the opposite," Abaddon tells Cecily's corpse.
Dean and Castiel take Gadreel to a warehouse where they bind him to a chair. After Gadreel regains consciousness, Castiel determines that most of Sam's internal burns have healed and Castiel should be able to fix the rest himself. Castiel questions Gadreel on his identity, not recognizing the angel despite having believed he'd seen every angel in Heaven. Gadreel definantly asks why he should tell them anything, but Dean states that he doesn't care who Gadreel is but he needs to get out of Sam immediately. "And if I don't?" asks Gadreel. "Then you and I will have a lovely little playdate," states Crowley. Gadreel threatens that even bound, he can rip Sam's body apart, but Dean warns that Gadreel will die if he does so. Gadreel challenges Dean to end it by putting an angel blade through Sam's heart. "If it makes you feel better, I have Sam locked away in a dream. As far as he knows, the two of you are working a case right now. Something with ghouls and cheerleaders."
Dean angrily demands to know why Gadreel is doing the things he is, pointing out that the two of them had fought together and Dean had trusted the angel and thought he was one of the good guys. "I am doing what I have to do," Gadreel insists. "Well so am I," Dean returns. Dean signals to Crowley who begins inserting pins into Sam's head to hack Gadreel.
As time passes and Gadreel screams in pain from all of the pins that Crowley is putting in his head, an emotional Dean can't take watching it anymore and leaves the room followed by a sympathetic Castiel. To distract himself, Dean asks about Castiel's state and how he became an angel again. Castiel admits that it wasn't easy, but Castiel feels that he didn't have a choice. "Yeah, well that's usually how it goes," Dean acknowledges. Dean then apologizes for kicking Castiel out of the bunker and not telling him about Sam. Castiel recognizes that Dean thought that Sam's life was at stake when he made the decision. "Yeah, I got played," Dean acknowledges. "I thought I was saving Heaven. I got played too," points out Castiel. "So you think we're both a couple of dumbasses?" questions Dean. "I prefer the word trusting. Less dumb, less ass," returns Castiel, a sentiment Dean agrees with.
Crowley then calls for the two, having finally succeeded in hacking the now-unconscious Gadreel. "Pinhead's out cold. But watch this." Crowley moves two of the pins, causing Gadreel to speak in Enochian. A shocked Castiel tells Dean that the angel is saying his name: Gadreel. Dean asks if the name means anything to Castiel, causing Castiel to explain "well that's why I've never seen him: he's been imprisoned since the dawn of time. Gadreel was the sentry who allowed Lucifer into the Garden." Growing angrier and angrier, Castiel explains that Gadreel is the cause of everything bad that's ever happened: the demons, the Apocalypse, God leaving, everything. Angrily grabbing Gadreel, Castiel shouts "you ruined the Universe, you damn son of a bitch!" Dean stops Castiel, understanding his anger but unwilling to risk hurting Sam because of it.
Crowley continues using the pins to hack his way through Gadreel to reach Sam with Dean getting impatient the longer it takes. Finally, Sam gasps and appears to regain consciousness. However, its not Sam but Gadreel who tells the group that "it won't work. You will never find your brother. Go ahead, poke and prod. I can sit in this chair for years and watch you fail over and over again. I've endured much worse than this Dean. So. Much. Worse. And I have all the time in the world." Dean orders Gadreel to shut up and decides to go to Plan B: to have Castiel possess Sam. "Get in there. Tell Sam what's going on and help him kick that lying son of a bitch out!" Dean orders. While Castiel admits that it might work, he can't possess a vessel without permission and they have no way of getting Sam to say "yes" to Castiel.
Crowley catches Dean's attention and Dean realizes that Crowley is suggesting that Crowley enact Dean's idea instead. Dean refuses, but Crowley reminds him that "demons can take what they want. I can burrow into that rat's nest of a head. I can wake Sam up. Just call me Plan C." As Castiel starts to protest, Dean realizes that Crowley is right and its their only chance. Crowley assures Dean that he'll work fast, but he'll run if confronted with the angel as he's not willing to die for them. However, Crowley demands his permanent freedom in exchange for helping them to save Sam in such a way.
After a moment to consider, Dean orders Castiel to "burn off" Sam's anti-possession tattoo, refusing to take no for an answer. Castiel reluctantly removes Sam's tattoo and Dean warns Crowley not to try anything while he's inside of Sam. "I keep my bargins. Besides I don't want to be inside your brother any longer than I have to. I'm not one for sloppy seconds," Crowley reassures Dean. Crowley sits down across from Gadreel and Dean removes the collar from around Crowley's neck. "When you find him, say Poughkeepsie. Its our go word, it means drop everything and run," Dean orders Crowley. As Castiel restrains Gadreel, Crowley agrees and Gadreel warns Crowley that "I will destroy you." "Eat me," quips Crowley before smoking out of his usual vessel and into Sam's body.
After Crowley enters Sam's body, Dean paces around the two unconscious vessels and comments "demon and an angel walk into my brother. It sounds like a bad joke." Castiel warns Dean that if the plan doesn't work, they will have to kill Gadreel even if it means killing Sam too. "It'll work," insists Dean.
Inside his own head, Sam is trapped in a dream of the bunker where he researches the ghoul case he believes that he and Dean are on. Crowley appears near Sam and looks around, commenting that its "not bad." Panicked, Sam calls for Dean before Crowley tells Sam "Poughkeepsie" as Dean had instructed him to do. Sam is caught by surprise that Crowley knows that word and Crowley explains that the real Dean has sent him to Sam. "I'll make this quick: you've been possessed by an angel. He's got you packed away in some dusty corner of your own mind and I'm here to break you out." While Crowley gestures for them to leave, Sam doesn't believe him. "Fine, we'll do this the fun way." Crowley picks up Dean's gun off the library table and shoots Sam in the chest to demonstrate that its not real.
"I know how possession works Sam. You've seen everything that he's seen even if you can't remember. So what I need you to do, I need you to remember," instructs Crowley. Concentrating, Sam gets flashes of his time possessed by Gadreel, including being unconscious in the hospital and Gadreel murdering Kevin. A horrified Sam asks if he killed Kevin, but Crowley reassures him that Sam didn't, Gadreel did. "You need to take control Sam, blow it up and cast that punk-ass holy roller out!" yells Crowley.
Looking up, Sam spots Gadreel standing behind Crowley in the form of Gadreel's old vessel. "Oh bollocks," comments Crowley, realizing what Sam is looking at. Crowley identifies Gadreel to Sam, calling Gadreel "the original chump." Gadreel states that he was a chump, but he will now be the one to lead his kind back to Heaven. Gadreel tells Crowley that he will be a hero while Crowley will always be a coward. "You should be running," Gadreel tells Crowley. Instead of running, Crowley punches Gadreel in the face to no effect. In return, Gadreel sends Crowley flying over the library table.
As Gadreel viciously kicks Crowley, Sam attacks. However, Gadreel just throws him over the table, knocking over a lamp in the process. Gadreel orders Sam to give up, claiming that Sam is not strong enough, but Sam retaliates with a kick to Gadreel's face. "Take control Sam, cast him out!" orders Crowley from across the room. Sam attempts to order Gadreel out of his head, but Gadreel grabs Sam by the throat and pins Sam to the floor. "You sure you want me to go? Maybe I'm the only thing holding you together. I leave you might die!" taunts Gadreel.
Struggling to breathe, Sam grabs the fallen lamp and smashes Gadreel in the face with it, stunning Gadreel and allowing Sam to shove the angel off of him and onto the floor. Pinning Gadreel to the floor with his foot to Gadreel's throat, Sam orders "I said. Get. The hell. Out!" With Sam's consent revoked, Gadreel is expelled from his body in a stream of white light.
At the bar, Metatron continues to wait for Gadreel who is now late. Suddenly, the lights flicker, the room shakes and the glass starts to shatter. "Yes", says the bartender and as Metatron watches, Gadreel enters the room in a stream of white light and repossesses his old vessel. Realizing what must've happened, Metatron comments wryly "let me guess. Winchester trouble?"
At the warehouse, Crowley returns to his usual vessel, leaving Sam completely himself again. Dean and Castiel rush to Sam's aid, removing the bindings and pins from his forehead. As Sam expresses surprise at Castiel's presence, Dean notices a car approaching. Checking out the window, Castiel finds Abaddon and two demons emerging from the car. "Go. The back door, I'll handle this," Crowley orders Dean. In response to Dean's skepticism, Crowley states that "I'm the goodest guy you've got." Dean reluctantly agrees, warning that saving Sam and taking care of Abaddon doesn't make them square and Dean will kill Crowley if he sees the demon again. "Pleasure doing business with you boys as always," Crowley quips sitting down in Gadreel's chair as Sam, Dean and Castiel flee.
The three demons enter the warehouse and Crowley greets Abaddon with "hello darling." Abaddon orders the two demons to bring her Crowley's head, but neither makes a move to do so. Crowley comments that demons are only obedient up to a point and states that he wants to talk. When Abaddon refuses Crowley goes on to say, as Abaddon descends to the warehouse floor, "I'm not talking to you, I'm talking to them, the average demon, because I feel their pain. It must've been terrible when your king was so cruely taken from you. I imagine you felt all at sea. And then along came... the brute. She's strong and a Knight and immortal at the moment, so I'm not surprised that some of my more idiotic subjects bought her line. But now, good news fellas: Daddy's home."
Standing in front of Crowley, Abaddon states that Hell no longer wants Crowley and it is now hers. Crowley tells her that that's not what he hears and its not something that will happen as long as he's still alive. Abaddon suggests a fight to the death then and there, but Crowley refuses, stating that its not a fight, something that Abaddon scoffs at. "Its a campaign. Hearts and minds, that's what's important. See the demons have a choice: take orders from the world's angriest ginger - and that's saying something - or join my team where everyone gets a say, a virgin and all the entrails they can eat. So think on this lads, spread the word. Vote Crowley."
Reaching safety on a dock, Castiel heals Sam's injuries from the pins. Castiel tells Sam that it will take time to fully heal him the remainder of the way from the Trials and they will have to do it in stages. Sam is left angry that Dean didn't respect his wishes when Sam wanted to die and Kevin is now dead because of it. Dean decides to leave to hunt Gadreel on his own and Sam doesn't stop him. While the two eventually start hunting together again, Sam refuses to be anything more than hunting partners until Dean is killed by Metatron and they reconcile.
Working over a period of weeks, Castiel is able to finish the healing on Sam that Gadreel had started. While they briefly stop the healing when its discovered that Gadreel left grace inside Sam that could potentially be used to track the rogue angel, Castiel completes the process when the grace extraction nearly kills Sam.
Following his expulsion from Sam and return to his old vessel, Gadreel resumes his work for Metatron. After realizing that he is on the wrong side, Gadreel defects to help the Winchesters and Castiel defeat Metatron. Dean nearly kills Gadreel for his actions, but is stopped by Castiel and Sam who work with Gadreel to defeat Metatron and retake Heaven.
After being set free in exchange for helping to save Sam, Crowley begins going to war with Abaddon for control of Hell. While Dean is separated from Sam, Crowley enlists Dean's help in finding the First Blade, the one weapon that can kill Abaddon. Despite their past differences, the Winchesters and Crowley form an alliance to battle Abaddon, ultimately leading to her death at Dean's hands and Crowley regaining full control of Hell.
- During their attempt to save Sam's life, Dean tells Crowley to use the word Poughkeepsie to warn Sam that something is wrong. In King of the Damned, Crowley uses this to warn Dean of Abaddon's trap. Sam later uses it in Season 14's Nihilism to get Dean to remember that he is possessed by the Apocalypse World Michael.
- In King of the Damned, while talking about his possession by Gadreel with Castiel, Sam states that Gadreel never took complete control of him. According to Sam, he was still himself and it was more like he and Gadreel were sharing head space. He also never got a sense of malice or a reason to be afraid while under Gadreel's control.
- In Hell's Angel, Crowley would try the same tactic of possessing someone to get the vessel to cast the angel out in an attempt to help Castiel cast out Lucifer. That time the attempt failed and Sam was forced to perform an exorcism on Crowley to save his life.
- In Season 14's Nihilism, Sam takes inspiration from this to try to free Dean from possession by the Apocalypse World Michael. With Crowley dead, Sam uses the British Men of Letters mind-link device instead to connect with Dean's subconscious mind.