what will hapen to intruder as gerrard

Your question was not clear to me. However, here is a brief explanation that might help you:

The intruder wanted to take Gerard's identity to escape the police. However, Gerard fooled him by saying that even he was fleeing from the police and needed to get away. Therefore, his identity would not be suitable for the intruder. Saying this, he tricked the intruder into getting inside a cupboard and locked it. Later we come to know that he was dressed up for a play and had thus worn props. He called the sergeant to arrest the intruder.

Hope this was helpful!