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 the hosts and that they have evidently been decoyed to the island. First one and then another dies; each death according to the rhyme of "Ten Little Soldier Boys". The tension grows as they realise that the killer is, in fact, one of themselves.