Trancers starts off in the neon-tinged year of 2247, where we find much of old Los Angeles (now called “Angel City”) submerged by the ocean. Law enforcement officers called “Troopers”, like Jack Deth (Tim Thomerson), are taking down (referred to as “singeing”) “trancers”, which are weak-minded people (dubbed “squids”) who can easily come under the hypnotic, homicidal zombie-like spell (“not quite alive, not dead enough”) of nefarious Charles Manson-esque cult leader Martin Whistler (Michael Stefani), who Deth sees as responsible for the murder of his wife. Deth thinks he has taken down Whistler once and for all, only to learn that the telepathic supervillain is still alive, but has avoided Deth (and death) by traveling back in time to Los Angeles in late 1985 with something called “time serum”, where one can go back through time by their conscience into the body of another person in their direct family lineage of the past.
There and then, Whistler hopes to terminate the ancestors of the three-person “High Council of the Western Territories” members who took him down in 2247. Jack Deth always gets his man, so he too goes back in time to stop Whistler once and for all, inhabiting his consciousness into one of his own ancestors, a sleazeball journalist named Philip Dethton, who happens to be a dead ringer. Along with Phil's young girlfriend Leena (Helen Hunt), Deth is going to be crafty to take down his target, as Whistler is inhabiting the body of his own ancestor, who happens to be an LAPD detective, and has already channeled a number of “trancers” to his cause to protect him as he tries to take down the last Council member's ancestor, a down-and-out, alcoholic ex-pro baseball pitcher currently living on Skid Row (Biff Manard).