Mr. Hamilton Lorne is amused to receive a card with the grotesque picture of a fool, complete with cap and bells, one finger pointing at the holder.

He and Superintendent Budd of Scotland Yard laugh at the threatening limerick scrawled across the back, assuming it is a feeble practical joke, and drop the card into a waste-paper basket.

But no one is laughing when the following morning Mr. Lorne is found dead, stabbed through the heart — the first in a series of sadistic murders perpetrated by the elusive Grim Joker…

This not-for-the-faint-hearted thriller will have you scratching your head and reaching for the light!