Before I Hang

Dr. John Garth stands trial for murder after mercy killing of an elderly friend. He argues his decision was an act of mercy rather than malice, hoping to spare the friend further suffering. The courtroom becomes a stage for questions about ethics, science, and the pressures of a physician who defies convention.

In court, Garth reveals that he had been researching a cure for aging but could not perfect it before his friend's pain became unbearable. He pleads for mercy and implies his work could help humanity. The judge sentences him to be hanged in three weeks.

While awaiting execution, Garth is allowed to continue experiments thanks to the warden and Dr. Ralph Howard. They develop a serum using the blood of a recently executed prisoner that they hope will reverse aging. The prison becomes a hidden lab where dangerous science proceeds behind bars.

The serum is administered to Garth immediately before the scheduled hanging. The injection triggers visible signs of youth and vitality, alarming both scientists and witnesses. He is being escorted to the gallows when the full effects of the experiment are observed.

A call informs that Garth's sentence has been commuted to life imprisonment. At the same moment, the serum's effects cause him to collapse, suggesting dangerous physiological side effects. The incident disrupts the execution and foreshadows the trouble to come.

Garth awakens in the prison medical ward to find that the serum has reversed some aging. His hair darkens and his body regains youth and vigor. He begins to believe the experiment may be a breakthrough worth pursuing.

Believing in the serum's promise, Garth plans to test it on Dr. Ralph Howard. He begins to prepare Howard, but the presence of the executed prisoner's blood seems to unlock a murderous impulse within him. He struggles to control himself as the urge grows stronger.

Garth strangles Dr. Howard during the attempted injection, then a wandering prisoner enters the room and is killed in the ensuing struggle. The deaths intensify the mystery around his behavior. He does not remember committing the murders.

Prison authorities discover the two corpses and misinterpret the events as Howard's murder and an attempted assault on Garth. Garth is hailed as a hero for surviving the ordeal and is granted a full pardon. He returns home to his daughter Martha and resumes his controversial anti-aging research.

Garth begins seeking test subjects among his aging friends, hoping to prove the serum's efficacy. Victor Sondini initially refuses, but changes his mind after a visit from Garth. The plan to demonstrate the serum's power moves forward, despite growing unease.

Garth administers the serum to Victor, but is again seized by murderous impulses from the prison blood. He chokes Victor before he can become a test subject. The episode confirms the serum's dangerous side effects and his loss of self-control.

Garth visits George Wharton to confess his crimes and request Wharton as the final subject. Wharton tries to call for help, but Garth kills him before anyone can intervene. The body count continues to rise as the truth remains hidden from those around him.

Martha begins to suspect something is wrong and confronts her father. Garth pleads with her to leave, claiming he can control himself, but she refuses to abandon him. The confrontation ends with Martha fainting as Garth loses control and advances.

Pursued by the police, Garth returns to the prison where the warden lets him in. He makes aggressive moves toward the armed guard at the gate and is shot. As he dies, he admits that he chose suicide to prevent himself from killing anyone else.