Into the Water Paula Hawkins

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.

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 !!