Ten People find themselves stranded in the lonely house on Soldier Island when their supposed hosts send word that they have been detained. A mysterious voice, afterwards discovered to come from a gramophone record, indicts each one of them – the eight guests and the two servants – of murder. It transpires that no-one has met their hosts and that they have evidently been decoyed to the island.
First one and then another dies, and then another.
The tension grows as they realise that the killer is, in fact, one of themselves.