On the day when Paul took a summer job at Repsom museum, the Gilbertson necklace was to the museum to be put on show. Meanwhile Paul started to work with Anna Wain on some displays about life in ancient Repsom. Two weeks later, the alarm off at 11 o'clock and when Paul and Anna went downstairs to see what , they saw that the necklace .
The thief the security camera in that room with a newspaper while he or she it. When the police , they all those who worked there and they Paul, since the necklace was stolen only two weeks after he started working there, and before, nothing ever . Apart that, only two years before, he with some friends who stealing packets of cigarettes. Meanwhile, Paul the necklace hidden in the treasure chest of the pirate display. He going to hand it over to the police, but then he that the police would think that he it and to have found it.
During the next few days, Paul various people. He suspected Anna Wain because she to the coffee machine at the time of the theft and she not the police about that. He also Cora Turner because her brother was a gambler who needed money. Another suspect was Ian Maxton because the week before, he an accident and his motor bike and the car which was involved in the accident. He was not insured, so he needed a lot of money.
Since the police suspected Paul, Mr Balfour him to find another job. Paul was very angry that he was going to have to leave the museum, so he to prove his innocence by the thief himself. He set a trap to catch him or her. He everyone at the museum that the next day he going to move everything from the platform of the pirate display in order to the platform.
That evening he to the museum, put on the uniform of a wax policeman and there like a wax dummy waiting for the thief to come. At midnight, Derek Halliday carrying a torch. When he up the necklace, Paul on the light and Derek admitted that someone him to steal the necklace.
Then Mrs Gilbertson with a gun to kill Derek and take the necklace. She to make it seem as if her necklace in order to get one hundred thousand pounds as insurance money and then more money by secretly selling the necklace because she become poor. She to kill Derek because he would keep asking her for more money to keep quiet. She him in the shoulder but he was not . Paul off the light and in the dark, she into the prison cell of the prison display. Paul her in. She and Derek were arrested and sent to prison. Paul a very good detective. He proved himself innocent and kept his summer job at the museum.