While executing an armored car heist in Los Angeles, icy crook Dave Purvis shoots policeman Lt. Phillips before he and his cronies make off with the loot. Thinking he got away scot-free, Purvis collects his money-crazy mistress, Yvonne, then disposes of his partners and heads out of town. What Purvis doesn't know is that Phillips' partner, tough-as-nails Lt. Cordell, is wise to the criminal's plans and is closing in on his prey.

Army Lieutenant Halliday, accused of stealing the Army payroll, pursues the real thief on a frantic chase through Mexico aided by the thief's ex-girlfriend and is in turn being chased by his accuser, Capt. Blake.

In 19th century England, a noted brain surgeon rescues a former student from being hanged on a false conviction for murder, and spirits him away to an ancient, repurposed abbey far in the countryside. There, he connives his pupil into assisting him in mapping the functions of the various parts of the human brain, using living subjects who are under a terrible animation-suspending drug called "black sleep". Subsequently, the student, along with the daughter of one of the subjects, discover that most of these subjects have survived but are being kept in a dungeon-like cellar, in various stages of physical and mental derangement...