One of the sillier German krimi films based on Edgar Wallace. This time Klaus Kinski is twins; one (Dave) was falsely convicted of murder and sent to an asylum, the other (Richard) goes missing the night Klaus-Dave escapes. Therefore, Klaus-Dave pretends to be Klaus-Richard, but the Scotland Yard Inspector figures out the difference. The thing is, when one of the murders is attempted, the Inspector is with Klaus-Dave.

Bottom line, there we are trapped in a house with a killer and the only guy we know ISN'T the killer is Klaus Kinsky. Uh-oh!

Anyway, from there we have a corrupt insane asylum, secret passages, boa constrictors, mannequins, and a ubiquitous music sting you hear like 5 times at the end.