Answer: The author creates surprise when he sets up the expectation that Phythias will take Damon's place when he returns, but finally both men are willing to die for each other.
Explanation: In "Damon and Phythias", Dionysius, the ruler of Syracuse, condemns Phythias to death after Phythias criticizes him and describes him as a cruel man. Phythias accepts his fate, but he asks the ruler for permission to return to his home in order to say goodbye to his family. As Dionysius is not sure whether Phythias will return, Phythias tells him that Damon, his friend, will take his place until he comes back. In that way, the audience believes that Phythias will take Damon's place again when he returns, but the author surprises the reader when Phythias comes back and both friends reveal they are willing to die for each other. Therefore, the author completes the story with a situation that the readers did not expect to take place.
