And Then There Were None; by Agatha Christie.

It seems unlikely that anyone would be unfamiliar with this story - so much is this been a part of growing up. The island where the chosen group has been invited to take a free holiday all paid, where they meet each other after a solitary journey and go on to the mansion to spend the holiday - only to find they are dying, one by one. They are being popped off, but they are only themselves on the island, and no one coming, no way to leave for anyone. It seems unlikely it could be one of them, and yet ...