Before I Hang.

Dr. John Garth (Boris Karloff) is on trial for murder after performing a mercy killing on an elderly friend. In the trial, he reveals that he had been researching a cure for aging, but had not had time to perfect it before his friend's pain became unbearable. As he awaits his execution, Dr. Garth is allowed to continue his experiments, thanks to support from the prison warden (Ben Taggart) and another scientist who is interested in his research. Using the blood of a recently executed prisoner, they succeed in developing a serum that will reverse the effects of aging and they decide to