Since writing this post, Imhave discovered a good website called Bookrags.com which gives a complete summary of each part of the book. In case anyone is reading the book currently Imwont answer my own question !!
Was going to answer your question Atqui but realised it might spoil it for others. Had a look at Bookrags and have to agree with suggested scenario. Didn't enjoy this book as much as Girl on the Train.