The Pennyfoot hides many secrets, and its downstairs staff keeps a tight lip, even when the Edwardian aristocrats are spotted dallying with damsels in the boudoirs or gambling in the card rooms hidden below the floorboards. Should now and then one of the hotel guests fall prey to a dastardly murderer, however, it is up to Cecily Sinclair to restore order before Scotland Yard steps in and shuts down her infamous seaside hotel.

A knock on the door in the dead of night, and seconds later, a man lies dead, poisoned by a mysterious substance. Who else could be to blame but the local herbalist – considered a witch because of her powerful potions?

Once again, Cecily Sinclair is called upon to discover the real killer before her best friend is thrown in jail for a crime she simply couldn't have committed.