The next mystery is told by Dr Pender, the clergyman.
He is invited to spend a weekend at the house of his friend Sir Richard Haydon. There is a group of people there: Elliot Haydon, his cousin, Lady Mannering and her daughter, Captain Rogers and his wife, Dr Symond and Miss Diana Ashley, a socialite. Dr Pender thinks that the reason of this gathering was Diana Ashley, who Sir Richard was clearly besotted with. Diana’s affections were fickle as at times she bestowed all the attention on Sir Ashley and others she acted as if he wasn’t there, paying all her attention to Elliot and Dr Symond.
Sir Henry showed the group a grove which was believed to have been a place of worship for Arstarte, the Phoenician goddess of Moon. Dr Pender thought that the atmosphere in the place gave negative vibes, and some of the others showed the same opinion of the spot. That night Diana persuaded everyone to have a costume party, and they all dressed up in different attires. When Diana’s absence was noticed, they found her at the grove, and she started to say she was the goddess and everyone who touched her would be dead. When Richard tried to approach her, he fell and when Elliot went to check on him, he realized Richard was dead, and the most shocking thing was that he had been stabbed in the heart, but there was no weapon. Diana was distraught, thinking that she had caused Richard’s death, and one of the lady guests claimed to have seen a dagger hidden up her sleeve, but nobody else had seen it. Then Elliott returned to the grove to find the weapon, but when he failed to return, the others went to search for him, they found him lying on the ground as he had been stabbed in the shoulder. His explanation later was vague as he had been unable to see anything.
When Dr Pender finished his account, the others came up with different paranormal explanations. Only Mr Petherick, the solicitor, thought that the explanation had nothing to do with ghosts, and Diana probably stabbed the man herself. It is once again Miss Marple, who comes up with the key to the case. It was Elliott who stabbed the man. He was dressed up as a brigand for the costume party, and Miss Marple guessed that he might have been carrying a knife of some kind, and when Richard tripped and fell, he was the one to check on him, and that was when he stabbed him to death. Dr Pender confirms her explanation as he got a letter from Elliott, confessing to the murder. He did so because he was in love with Diana Ashley, and he thought that if he got rid of his cousin, he would have a chance. Then his life became hell, and he wrote the letter to Dr Pender before he went on an expedition to the South Pole because he feared he might not return, and he didn’t.