Steed is trying to infiltrate a group of assassins currently based in the South of France. He robs the leader of some jewellery in order to impress him, then waits for them in the local club. It just so happens that Venus Smith is singing there.

A man involved in a car crash is found to have fifty thousand pounds worth of diamonds in his stomach. Steed investigates the man's joke shop, Big Laugh, and then the offices of multi-millionaire Litoff. The burial of one of Litoff's Great Danes is not quite what it seems.