Richard Samson is a London attorney who receives a visit at his home from an old friend, Alan Rennick. The circumstances prompting this visit are unpleasant. Rennick has just murdered his butler, Baines. The butler had stolen letters and then tried to blackmail him, so Rennick bashed him in the head with a poker. Now he wants his friend and attorney to hide him, or he will kill him too. Samson agrees, but nearly levels his old chum by explaining that while in hiding he will have to do his own laundry, cooking, and serving. Clearly, Rennick hadn't considered all of the ramifications of murdering his butler.
Rennick stays in hiding at Samson's flat until his escape can be carried out. He asks his friend Margaret Farley to help and soon a plan is in motion. Their idea is to fake his death so he can assume another identity. Anita Kilner, the lady-friend who had written the letters stolen by the butler, is also called in to help. All four of them set out on a frosty night to stage the "accidental drowning" in the river. Unfortunately for Rennick, the plan doesn't play out as expected.
(Image of the Old Bailey in London from Wikipedia.com)