The Girl on the Train by Paula Hawkins

There are some problems that librarians generally don't have.  For example, which limo service to take.  However, there are problems that librarians do suffer.  In my case, I suffer from the librarian problem of "can't sleep because a book is too good."  

The Girl on the Train was a source of the most recent occurrence of this librarian problem for me.  The last time I had this problem was last year when reading Andy Weir's The Martian.

• There have been a number of comparisons between The Girl on the Train and Gone Girl.  In my opinion, The Girl on the Train is more engaging.  Hands down I prefer The Girl on the Train.
• Each of the main characters is surprisingly complex.  
• Even in the end, I'm not sure who I should trust.