Trancers

Jack Deth (Tim Thomerson) is a police trooper in the year 2247 who has been hunting down Martin Whistler (Michael Stefani), a criminal mastermind who uses strange psychic powers to make people into zombies that carry out his every desire. Deth can identify a tranced victim by scanning them with a special bracelet. All trancers appear as normal humans at first, but once triggered, they become savage killers with twisted features.

Before he can be caught, Whistler escapes back in time using a bizarre, drug-induced time traveling technique. Whistler leaves his body in 2247 and travels down his ancestral bloodline arriving in year 1985 and taking over the body of an ancestor who happens to be a Los Angeles police detective named Weisling.

Once Deth discovers what Whistler has done, he destroys Whistler’s body – effectively leaving him trapped in the past with no vessel to return to – and chases after him through time the same way. Deth himself ends up in the body of one of his ancestors; a journalist named Phil Dethton.

With the help of Phil’s girlfriend, (a punk rock girl named Leena (Helen Hunt)), Deth goes after Whistler who has begun to “trance” other victims and plots to eliminate the future governing council members of Angel City, (the future name of Los Angeles), who are being systematically wiped out of existence by Whistler’s murder spree of their own ancestors. Deth arrives too late to prevent most of the murders and can only safeguard Hap Ashby (Biff Manard), a washed-up former pro baseball player who is the ancestor of the last surviving council member Chairman Ashe.

Deth is given some high-tech equipment which is sent to him in the past: his sidearm, (which contains two hidden vials of time drugs to send him and Whistler back to the future), and a “long-second” wristwatch, which temporarily slows time stretching one second to ten. The watch has only enough power for one use but he receives another watch through time later to pull the same trick again.

During the end fight with Whistler, one of the drug vials in Jack’s gun breaks, leaving only one vial to get home. Jack then makes the choice to kill Weisling (who is possessed by the evil Whistler), or use the vial to send Whistler back to 2247. Jack injects Weisling with the last vial sending Whistler home, but with no body to return to, he effectively destroys him. Jack then decides to remain with Leena in 1985, although observing him from the shadows is McNulty, his boss from the future, who has traveled down his own ancestral line and ending up in the body of a young girl.
[edit] Production & release

This film uses a method of time travel: People can travel back in time by injecting themselves with a drug which allows them to take over the body of an ancestor. When Jack Deth arrives in 1985, he is in the body of his ancestor, a journalist; Whistler assumes control of his ancestor, a police detective; and Deth’s supervisor, McNulty, borrows the form of his own forebear, a young girl.

Because of Helen Hunt’s rise to fame in the 1990s, the DVD re-releases of the first two films have Helen Hunt’s name listed first, then Tim Thomerson and Michael Stefani, respectively.

From Wikipedia