The “pit of darkness” in this British B-flick is amnesia. That’s what happens to straight-arrow businessman William Franklyn after he wakes up outdoors in the middle of the night with no memory of the past three weeks. All he knows is that he seems to have connections now to a gang of crooks. Also, a mysterious woman keeps calling his house, which pisses off the wife a tad. Over the next seventy-eight minutes, plots thicken, shots fire, punches fly, clues arise and a guy falls off a roof. It passes the time all right. Lead actor Franklyn does okay here for a guy who has about a half a teaspoon of screen charisma in him. Also, if you feel like it, look for future members of The Dave Clark Five as the schmaltz-slinging house band of a posh nightclub.