Offers a modern twist on Agatha Christie's most famous whodunit, And Then There Were None. Detective story writer Antonia Darcy and her husband Hugh Payne are asked to travel to Devon in order to prevent a murder on Sphinx Island, but they are far from enthusiastic as they suspect an elaborate joke. And when they hear that one of the house party guests is Romaine Garrison-Gore, another crime writer, they have no doubt that they will walk into a rather tedious variant of the Murder Weekend. After all, it is their 10th wedding anniversary and Major Payne's aunt, Lady Grylls, has been trying to think of a truly original present for them. But then they receive a rather sinister letter signed "The Riddler" and become curious--could the devil speak true?