(一) A Trap Mr. Smith left his car outside his apartment one night as usual, but when he came down the next morning to go to his office, he discovered that the car wasn’t there. He called the police and told them what had happened, and they said that they would try to find the car. When Mr. Smith came home from his office that evening, the car was back again in its usual place in front of his house. He examined it carefully to see whether it had been damaged, and found two theater tickets on one of the seats and a letter which said, “We’re very sorry. We took your car because of an emergency.”