Lucifer takes a new host body: the President of the United States. The Winchesters are forced to turn to the British Men of Letters for help to remove Lucifer's essence from his new host, but the Secret Service has other ideas.

When Castiel's former angelic squadmates turn up dead, he goes to investigate and the Winchesters insist on tagging along. They soon discover that the killer has a grudge against angels... and one in particular.