|There was something about being there... It felt pure.|
This episode summary is an official CW press release. It may contain errors.
DO NOT CHANGE!
Sam and Dean investigate a case in Chicago, where they discover that various mafia-esque monster families are, unknown to humans, running the underbelly of Chicago. One is a family of shapeshifters run by Margo Lassiter (guest stars Danielle Savre), whose leadership is thrown into question when her brother David (guest star Nathaniel Buzolic) returns home. The other reigning family in town is made up of werewolves, lead by Julian Duval (guest star Sean Faris). While in Chicago, Sam and Dean meet Ennis (guest star Lucien Laviscount), a man with a personal vendetta against the monsters. The Winchesters warn Ennis about heading into the hunter lifestyle, but Ennis refuses to listen and starts down a dangerous path.
Ennis Ross is taking his girlfriend Tamara to upmarket restaurant "Il Secundo", with the intent of proposing to her. As he speaks with Maurice the maitre d' about hiding the engagement ring in a glass of champagne, they are interrupted by Sal Lassiter. The matire d' ignores Ennis to accompany Sal to the private club in the back, and as they leave Ennis catches a glimpse of the bodyguard Marv's face in the mirror where his reflection is grotesque.
The private club is full of monsters of different types socialising. At the bar Sal - a shapeshifter - is approached by werewolf Julian Duval, who isn't pleased to see him. They get into a fight, but their bodyguards pull them apart, and Julian leaves. Soon after a masked figure, with what looks like silver claws arrives and starts killing.
Sal is injured and staggers outside to the pier where Ennis is about to propose to Tamara. The creature follows, and as it attacks Sal, it pushes Tamara out of the way. She falls, hitting her head and dies. The creature rips out Sal's heart and flees. As Sal lays dying he says to Ennis "David - I had no choice."
Later at the police station Ennis tries to explain to Detective Costa what he saw but the detective, despite being a friend of Ennis' late father who was also on the force, doesn't believe him. Sam and Dean arrive pretending to be FBI agents. They listen to Ennis' story and then leave, warning him that monsters aren't real.
At the Lassiter home, eldest daughter Margo is consulting with Detective Costa, who is on the Lassiter payroll. He tells her that the ghoul family may not support the Lassiters if she moves against the Duvals. He points out that the other four monster families are looking to take more power now that Margo's father is dying.
David Lassiter, youngest son of the Lassiter family, returns home for the first time in three years after Margo calls to tell him that Sal has been killed. David finds Margo's henchmen preparing a cache of weapons. She is blaming Julian Duval for Sal's death and wants war. David is shocked at how his father's health has deteriorated since he has been away, and he advises Margo against war with the Duvals. Margo mocks him, accusing him of supporting the Duval's because he used to date Violet Duval. She takes delight in telling him that Violet is being married off to a New York werewolf family to forge an alliance.
Julian Duval is meeting with one of the Djinn family, and they discuss how the Lassiters may respond to Sal's death. Violet interrupts, demanding to know if it was Julian who killed Sal. He denies it, and says he doesn't care as long as it brings on a war with the shifters. He reminds her she has no power in the family.
At home, Ennis pulls out a trunk of his father's. He takes out a revolver and finds, hidden in the box, a collection of silver, engraved bullets. He returns to the club behind the restaurant and is confronted by the maitre d'- who is a vampire. Ennis shoots him to no avail. Dean comes up behind the vampire and decapitates it with a machete.
Sam gives Ennis a quick run down on the fact that monsters exists, while Dean discovers stores of blood and flesh behind the bar. The Winchesters theorize that maybe Sal Lassiter was a monster of some sort and plan to head to the morgue to check it out. Ennis insists on accompanying them but they warn him off getting involved.
Returning home, Ennis starts researching Sal Lassiter online, when Freddie Costa knocks at the front door. He comes in and starts asking the same questions he had the night before. Suspicious, Ennis manages to sneak a picture of Freddie, and he notices his eyes flare in the photo, which Sam and Dean told him was a sign of a shapeshifter. He asks if Freddie wants to wait to talk until Ennis' dad gets home, and he agrees. This confirms Ennis' suspicions as the real Costa knows that his father is dead.
Ennis throws his jacket at Costa, and manages to pull his gun, loaded with the silver bullets, on the shifter, who changes revealing himself to be David Lassiter. He explains that he is trying to find out who killed Sal and avert war with the Duvals. He looks at Ennis' jacket and finds flecks of silver in the shreds, ruling out a werewolf being the clawed killer.
That night Ennis scopes out the Duval mansion. Sam and Dean are also there, and Ennis overhears them discussing that Julian Duval paid the coroner to look at Sal's body. They speculate that he wouldn't have done that if he himself was the killer. Violet Duval leaves the house, and David appears, telling her he wants to arrange a meeting between Julian and Margo to broker a peace agreement. Violet argues that Julian doesn't want peace. David brings up an old issue - years ago they were going to run away together, but Violet didn't turn up to the rendezvous.
Just then, the clawed killer appears and knocks David down before abducting Violet. Her screams bring Ennis and Sam and Dean running but the killer and Violet have gone. The Winchesters, Ennis and David leave as the Duval bodyguards swarm the grounds.
David explains to the Winchesters and Ennis that five monster families rule Chicago. He suggests they track Violet using the GPS in her phone, but he will only give them her number if he can come along. Sam and Dean agree, to Ennis' shock, but Dean explains that sometimes you need to make alliances with the bad guys - to catch the guys who are worse.
In an abandoned building, Violet is bound, her captor - a human called Irv -explains that Sal and a group of monsters killed his young son. He is trying to make the different families go to war against each other in revenge. Meanwhile, Sam, Ennis, Dean and David, have tracked Violet's cell phone signal to the building. As they search it, Ennis tells David what Sal said as he died.
Irv manages to capture David. He starts to torture him with his silver claws, and Violet becomes enraged, transforming into a werewolf and attacking Irv. David manages to pull her off just as the Winchesters and Ennis arrive. Irv makes a half-hearted apology for killing Tamara, saying she was in the way, but Ennis kills him.
The next day David visits Violet, and muses over his brothers final words. Violet remembers - without telling David - that the night they were meant to leave together, Sal intervened and told her not to go because the families must keep the bloodlines pure. In the present day, as she is about to leave she turns and kisses David.
At the Lassiter home, his ailing father warns David not to let Margo start a war. David goes and tells Margo he has found out that Sal's killer was not Julian Duval, and that he is now returning home - to the family business.
Sam and Dean Winchester reluctantly leave Ennis after getting a call from Castiel that he has found Metatron. They warn Ennis to stay away from the monsters, and advise that they will send some hunters to clean things up.
However Ennis returns to Irv's lair, and is examining all the information Irv collected on the monster families. His phone rings and a voice tells him not to get involved. It is the voice of the father he thought was dead.
- Danielle Savre as Margo Lassiter
- Nathaniel Buzolic as David Lassiter
- Lucien Laviscount as Ennis Ross
- Sean Faris as Julian Duval
- Bryce Johnson as Sal Lassiter
- Melissa Roxburgh as Violet Duval
- Gardiner Millar as Irv Sokolowski
- Stephen Martines as Freddie Costa
- Erinn Westbrook as Tamara
- Leo Rano as Marv
- Somehow by Caught a Ghost
- Looking Glass / Pettibon by ERAAS
- Little Black Submarines by The Black Keys
Featured Supernatural Beings
- Angel (Castiel and Metatron, mentioned only)
- Ghouls (mentioned only)
- Shapeshifters (Margo Lassiter, David Lassiter, Sal Lassiter)
- Werewolves (Julian Duval, Violet Duval)
- Wraiths (Marv)
- This episode has the lowest user ratings on IMDb of the entire series.
- Out of 2,878 votes, it received a 6.0 rating.
- This episode served as a backdoor pilot for the [now cancelled] Supernatural spin-off Supernatural: Bloodlines. Unfortunately, the spin-off never made it off the ground as this was the show's lowest rated episode in 9 seasons.
- Writer Andrew Dabb spoke on why he believes Bloodlines ultimately didn't work. "I think the biggest problem for us was, number one, timing. Our idea in hindsight was probably a little too similar to The Originals. We wanted to do something set in the Supernatural world but very unlike Supernatural. At that point, Supernatural [was] going strong. We didn't know when it was ending but it certainly didn't feel like it was on its way out and so we were really worried about taking any elements from the show." 
- Several co-stars present in this episode portrayed another character from previous episodes:
- Nathaniel Buzolic, Sean Faris and Stephen Martines also have roles in The Vampire Diaries, while Erinn Westbrook had a role its spinoff Legacies.
- The theme of Supernatural: Bloodlines shares similarities to the theme of The Originals, another The CW show, where communities, both Supernatural and otherwise are struggling for domination in a heavily populated city.
- The monster families running Chicago were shapeshifters, werewolves, and djinn with ghouls being mentioned as the fourth. Had The CW picked up Supernatural: Bloodlines, the fifth family was to be revealed as sirens.
- This is the episode where the most supernatural beings are featured together during the entire series run: a total of 8.
- The Impala in this episode was owned by a fan.
- The CW's official summary for this episode mistakenly writes 'guest stars' instead of 'guest star'.
- Sam and Dean use the FBI aliases of Bonham and Peart, a likely reference to John Bonham and Neil Peart, drummers for Led Zeppelin and Rush, respectively.
- Unlike other shifters in the series, the ones in this episode didn't have to shed their skin in order to shapeshift into someone else.
- Hungarian: Vérvonalak (Bloodlines)