The Baldwin Insane Asylum in Barstow, California, has recently burned to the gound in an inferno that cost many inmates their lives and injured scores. Now, Hook Runyon has been put in charge of security for a train that is to transport the survivors, alongside the head of the asylum, Dr. Baldwin, the attending doctor, taciturn Dr. Helms, and a self-sacrificing nurse named Andrea, to a new location in Oklahoma.

Hook hires a motley crew of WW II veterans to help, and they set out for the new destination. But things go awry on the Insane Train, as several inmates and attendants are found dead, and Dr.Baldwin seems increasingly disoriented and incapable of running operations.

With Andrea's help, Hook begins investigating the suspicious deaths, and uncovers a trail of revenge that has been a long time in the planning...by a person as mentally disturbed as her charges.