Classic chiller stars Boris Karloff as a doctor who is sentenced to death for his involvement in a mercy killing. While awaiting execution, he works on an experiment using a fellow prisoner's blood that could potentially reverse the aging process. But after he injects himself with the serum, his sentence is commuted, and he discovers the deadly side effects of his research. With Edward Van Sloan, Evelyn Keyes. Standard; Soundtrack: English Dolby Digital mono.