Rosalee Fearnley is being forced by her stepfather to marry a wealthy man whom she doesn't love against her will. She is taken to a country hotel, where she is to be handed over the following day to the man, Mr Rupert Sykes-Bailey. In effect, the stepfather is selling his stepdaughter and her inheritance to pay off serious gambling debts. In the hotel, things take a somewhat unexpected and mysterious turn. On arrival, stepfather Julian Best is allocated room 3, whilst Rosalee and her companion are allocated room 13. The room however, mysteriously disappears...