Bridget’s twin sister emails to say that she is coming to visit. They agree not to tell Annie and the boys, so that they can have some fun. Hector is sympathising with Bridget: they both seem to have difficult mothers. Nick has got another TV job, this time as a doctor in a soap opera. He is determined to practise on Hector.
Bridget’s twin sister arrives. She looks identical but has a very different personality. She loves doctors and is very interested in Nick. This is confusing, as Bridget certainly does not seem interested in Nick.
The confusion builds and builds as the two ‘Bridgets’ seem to contradict each other all the time, and no one can work out what is going on. Finally Annie sees both sisters at the same time. The three girls decide to play a trick on the boys and set up an elaborate magic show where Bridget is made to disappear and reappear.
The boys are puzzled until all is revealed.