Episode 15, "Death in Inner Space" is a slight cut above most entries, set in the isolated château outside Paris of Dr. Charles Hodek (Karel Stepanek, who receives co-star billing with Boris Karloff during the opening credits). Colonel March has already spoken to the Society for Interplanetary Communication, where he is invited to spend a few days with Dr. Hodek, who believes he has received radio waves from Mars during an experiment conceived by Professor Rogel (Christopher Rhodes). Seeking a way to suspend a person's life functions during space travel, Hodek has a volunteer in Philip Rosea (Michael Allan), his wife Annette's secret lover, who dies from a lack of oxygen despite the alarm set up to alert Hodek of any problems. Annette Hodek (Rosalie Crutchley) is immediately suspected by the doctor's lawyer, Paul Lavois (Peter Illing), who also has misgivings about Professor Rogel, who he feels is fleecing the trusting Hodek of funds vital to the experiment. Ewan Roberts as Inspector Ames does not appear in this episode, which, for once, features a genuinely surprising, yet perfectly logical solution.