It is the autumn of 1917, and at the luxurious Lotus Hotel in Chelsea, a maid is disrupted from her morning rounds by a horrifying discovery: instead of the dignified older lady who has been occupying a room, she find the dead body of a much younger woman. Harvey Marmion and Joe Keedy are dispatched from Scotland Yard to investigate, and learn that she seems to have been poisoned. But who is this woman? And what has happened to the previous occupant of the room? With a high profile client to impress, Marmion and Keedy must solve the mystery as quickly as possible, before the reputation of the hotel is damaged beyond repair.