The TARDIS takes the Doctor and Peri to the planet Necros, where the Doctor plans to visit his old friend Professor Arthur Stengos. But after an encounter with the Great Healer, Stengos is not quite the man the Doctor once knew. The Great Healer works in the catacombs beneath Tranquil Repose, the galactically-famous final resting place for the dead and the not-quite-yet-dead. In the upper chambers the busy workers prepare the deceased for their final burial, while deep below the Great Healer is using their bodies for a sinister project of his own.