Jeremy Johns was leaving Los Angeles to propose to his girlfriend when the city was sent to hell by the Senior Partners of Wolfram & Hart. In hell, Jeremy was rescued from a pack of werewolves by a vampire-with-a-soul named Spike and his demonic friend Illyria. Jeremy joined the group of humans following Spike and Illyria for protection, and began functioning as Spike's right hand man, despite Spike's continual insistence on referring to him as "Jerry".
Spike's team was kidnapped and held captive by the demon Non, who fed off the lifeforce of humans. When Non began using Jeremy's lifeforce, Illyria horrified Spike by punching a hole clean through his chest, believing that she was doing a good thing. Spike buried Jeremy under a grave marked "Jeremy Johns. A Friend."
When Angel's death caused the Senior Partner's to reverse time and undo the Fall of Los Angeles, Jeremy was resurrected along with everyone else, albeit with full recollection of their time in hell. He finally reached his girlfriend and proposed.Tor a demon working as a new liaison to the Senior Partners for Wolfram and Hart's Las Vegas Branch. Jeremy was used to approach Spike and prevent him from "killing the messenger." Drusilla murdered the demon in his true form, which unfortunately left him stuck in Jeremy's body. Jeremy was left in an unconscious state, and was taken by Spike. Later on witch Willow Rosenberg moved Tor into the body of a dead snake. In an attemt to rescue Beck and Betta George, Jeremy is attacked by Drusilla as a response to seeing Spike and Beck kiss. Jeremy does survive though.
- Even though he's human, Jeremy has been uniquely lucky. He was killed by Illyria (later on brought back to life) and then survived an attack from Drusilla. Both things not many live to tell
- Brian Lynch modelled Jeremy after the character Jim Halpert from the American version of the TV series The Office.