Rachel Watson
The protagonist, Rounded, Dynamic.
Rachel Watson used to be a happy and healthy woman before the divorce. Rachel turned to alcohol when her doctor told her something that no woman wants to hear. Rachel's ex-husband cheated on her because of the "alcohol." Rachel rides the train every day and rides past the house she used to live in with Tom, which is now him and his family's home. She looks out the train window to look at the old life she used to have, and the house down the road, where a happy couple lives, well Rachel thought they were happy until one day she saw Jess kissing another man that wasn't her husband.
Anna
The antagonist, Flat, Static.
Anna is the woman that stole Rachel's man and had his child. Anna has a lot of hate for Rachel and thinks she is crazy and will hurt her family. Anna goes behind Tom's back towards the end of the book and goes through his emails and gym bag when she finds something she never thought would be possible.
Megan Hipwell (Jess)
Rounded, Dynamic
Megan is married and in love with Scott Hipwell, but messes around with other men. Megan goes to a therapist, Kamal, which was suggested by her husband. Megan slowly opens up to Kamal and develops a little feeling for him in the process of telling him her life story. Megan wouldn't dare to tell Scott what her past life was like because she knew he would leave her, but maybe he would have been able to save her if she would have opened up to her husband and not some stranger.
Tom Watson
The Antagonist, Rounded, Dynamic.
Tom used to be married to Rachel, then slept around and got divorced. He is now married to Anna. Tom is the biggest liar in the book, he lies to every person he says he loves. Tom also has anger issues, but know how to get the ladies. Tom is an attractive man, hence all the woman he gets within the book.
Scott Hipwell (Jason)
Rounded, Dynamic.
Scott is Megan's husband and a very caring guy with some anger issues. When his wife goes missing his world goes upside down and he no longer cares for himself. He drinks all day, doesn't shower, and doesn't clean the house.
Dr. Kamal Abdic
Flat, Static.
Kamal is Annas therapist in the book and helps her deal with her big secret that she can't tell anyone, not even her husband. Anna and Kamal have a connection when they are together, they trust each other.
Cathy
Flat, Static.
Cathy and Rachel were friends in college, and Rachel has lived with Cathy ever since her divorce. Cathy is the one character that knows about Rachels drinking problem and tries to help her out by making her go to an aa group and finding her another job.