Metamorphosis

Geneticist Peter Houseman starts experiments on a serum that might prevent aging and defeat death, developed with the help of his friend Mike and young collaborator Willy. He tests with modified DNA in a private university laboratory. The aim is revolutionary, but the project attracts skepticism from funding bodies.

A university commission reviews Peter's requests for funding. Members, including the elderly Professor Lloyd, scrutinize the project and question its viability. Peter's enthusiasm clashes with bureaucratic caution.

Frustrated by funding delays, Peter administers the serum to his own body. At first, he experiences increased strength and vitality. The early signs boost his confidence.

As strength returns, Peter begins a romantic relationship with Inspector Sally. Her son Tommy is hostile toward him.

Tommy's hostility toward Peter grows as the peace of the house is unsettled. This tension foreshadows the trouble ahead.

Peter goes to a club and brutally beats a prostitute, later unable to remember the assault. The act marks the first clear outbreak of violence as the serum seems to destabilize his behavior.

Patricia, a flirtatious student who had tried to seduce him, is raped and strangled. The killings escalate as Peter's grip on reality slips and his alien physiology quietly begins to emerge.

Alongside the killings, Peter's body regresses, gaining reptilian features and a growing sense of invulnerability. Medical indicators begin to point to a deeper degeneration rather than aging.

Peter is hit by a police car and is admitted to hospital, where he undergoes a phase of premature aging that leaves him weakened. Doctors Mike and Lloyd monitor his condition as his body deteriorates.

Lloyd hypothesizes that Peter's body is regressing to an earlier stage of evolution, explaining the monster-like changes. The theory fuels the tension as the doctors debate how to treat him.

Peter escapes from the hospital, killing Lloyd and Willy on the way, and discovers that his body requires human blood to stay strong.

He kidnaps Tommy and returns to the university lab, leaving a trail of death and blood as he makes one last attempt to fix the experiment.

Tommy destroys the bottle containing the serum, halting the last hope of a cure. Sally helps protect Tommy, while Mike and the police await outside.

Peter, now an anthropomorphic dinosaur-like monster, opens the door and is shot by the police, then completely decomposes.

Some time later, Tommy shows his mother a lizard, implying Peter's survival inside it. When Sally tells him to let it be free or it will die, the boy says that it will never die.