The Reimprisonment of Lucifer was an effort undertaken by hunters Sam and Dean Winchester, the Seraphim Castiel, the demon Crowley and the witch Rowena to reimprison the fallen archangel Lucifer in Lucifer's Cage.
After the release of the Darkness, Sam started receiving visions from what he believed to be God directing him to Lucifer's Cage. Sam came to believe that God wished him to seek out the fallen archangel Lucifer for help with defeating the Darkness and using a spell from the Book of the Damned with the help of the witch Rowena, Sam spoke to Lucifer in Limbo. However, Lucifer was the one who had really sent the visions and trapped Sam with him in an attempt to get Sam to give him permission to take Sam as a vessel once more. Sam refused and Lucifer was apparently sent back to his cage, but in reality escaped by taking Castiel as his vessel. Lucifer eventually reconciled with God and aided the Winchesters and God in battle with the Darkness, but was expelled from Castiel when the attempt to imprison the Darkness failed.
Following the Darkness and God leaving the Earth, Lucifer came to believe that God had only been using him to defeat the Darkness and became bitter again. Lucifer began seeking out a new vessel, eventually settling on aging rock star Vince Vincente. After Vince burned out following a failed attempt at a massacre, Lucifer began seeking vessels with power and influence, leading to his possession of the President of the United States, Jefferson Rooney. Possessing Rooney, Lucifer impregnated his lover Kelly Kline with his child, a Nephilim and sent the Secret Service after the Winchesters.
After learning of Lucifer's possession of Rooney, the Winchesters and Castiel are rescued from the Secret Service by Arthur Ketch of the British Men of Letters. Amongst Arthur's arsenal was a hyperbolic pulse generator capable of forcing any angel or demon from their vessel and after getting Arthur to give it to them, the Winchesters, Crowley, Castiel and Rowena come up with a plan to send Lucifer back to his cage.
In order to draw Lucifer into the open, Crowley kidnaps Kelly Kline who is pregnant with his child. The Winchesters, Castiel, Crowley and Rowena convince Kelly of the truth about Lucifer's possession of Jefferson Rooney and convince Kelly to call Lucifer and draw him to their motel.
Following Kelly's phone call, Lucifer arrives at the motel with two Secret Service agents who search the room for any sign of someone other than Kelly. The leader discovers Castiel in the closet, but Castiel hypnotizes the man to believe that no one else is in the room and lead the agents outside to the car.
Lucifer enters the motel room where Kelly tells him that she can't have the baby. Enraged, Lucifer starts strangling Kelly, telling her that he will have to insist that she does. Sam then enters and uses a sigil to significantly weaken Lucifer's power, amusing him. Sam then activates the hyperbolic pulse generator, causing Lucifer to start to be exorcised from Rooney. Though Lucifer attempts to throw Sam, Dean, Crowley and Rowena with telekinesis, the sigil causes his power to be weakened to the point it barely harms them. As the generator begins effecting Lucifer, Dean signals Rowena who starts the spell to banish Lucifer back to his Cage. As the generator continues to exorcise him from Rooney, Lucifer yells that it isn't over to Sam who simply tells him to "go to Hell." Finally, the hyperbolic pulse generator exorcises Lucifer from Rooney in the form of a cloud of white smoke. With Lucifer out of his vessel, Rowena's spell sends him through the floor apparently back to his Cage where Lucifer is imprisoned once more.
Following Lucifer's defeat, Castiel finds that Jefferson Rooney is still alive and erases his memory of his possession by Lucifer. Shortly afterwards, the Winchesters are discovered by the Secret Service over Rooney's unconscious body and are believed to have been attempting to assassinate Rooney due to Lucifer's manipulations. As a result, the Secret Service arrests the Winchesters for attempting to assassinate the President of the United States. They later escape and everyone who knows about their arrest is killed by Arthur Ketch of the British Men of Letters.
Though Lucifer is believed to have been imprisoned once more in his Cage, he in fact becomes Crowley's secret prisoner. Crowley eventually explains to Lucifer that he perverted the spell Rowena used so that instead, it sent Lucifer into the repaired and improved body of Nick who was bound with chains made through study done on Lucifer's Cage. As a result, Lucifer is left Crowley's prisoner in his now-permanent vessel of Nick.