After the storm on the night of Dr. Armstrong's disappearance, the weather is fine again. Vera Claythorne and Philip Lombard are looking out to sea when Lombard notices what he thinks must be a pile of clothes. When they move closer to investigate, Vera sees that the object is actually the dead body of a man. Lombard looks at the face, which is purple, and sees that it is Dr. Armstrong himself.

Vera and Lombard have just been speculating on what could have happened to Dr. Armstrong. The previous night, Blore had thought he heard Armstrong moving about the house, and he and Lombard had gone out to search the island for him. They found nothing and came to the inconclusive conclusion that Armstrong had simply disappeared. The only place for him to have disappeared into was the sea. However, since so many matters remain unexplained, they begin to wonder if Dr. Armstrong could be hiding somewhere after all. Agatha Christie is at pains to point out that the house on Indian Island is very modern and has no secret passages or hiding places, as an old house might. Still, they begin to imagine that Dr. Armstrong may be alive an concealed somewhere. The events at the end of chapter 15 remove this suspicion definitively.