Rachel (Emily Blunt) is the girl on the train. She rides the train into the city every morning to go to work then rides the train home in the evening. In her spare time, Rachel sketches in a pad. Her sketches are quite good. Along her route, Rachel becomes infatuated with a husband and wife. To her, they are the perfect couple representing a life she could have had but lost.

Rachel is an alcoholic. She is divorced because of her drinking. Rachel hides her drinking from everyone. As every recovering alcoholic learns the hard way, the only person they are fooling is themselves.

Rachel is haunted by her past but cannot, or will not leave the past behind until she she has no choice.

Megan (Haley Bennett) is the woman Rachel has been watching from the train. In a flashback sequence, Rachel is meeting with her therapist Dr. Kamal Abdic (Edgar Ramírez). Rachel's husband wants to start a family. Rachel wants nothing to do with children. To help make up her mind about having children, her husband suggests she take a job as a nanny.

Director Tate Taylor uses the flashback very early on in the film thus blurring the lines between reality, past, present and future. What does this have to do with Rachel?

Anna (Rebecca Ferguson) is a mother who loves her husband and new baby. To help her with her baby and other chores around the house, Anna has employed a nanny. Megan is the nanny. Anna complains that the number of telephone hang ups is increasing. The calls are from Rachel. Anna is married to Rachel's ex-husband Tom (Justin Theroux). Thus, the three women are linked.

But, the immediate question is: when did this sequence between Anna and Megan take place? Is this a flashback to the time when Megan met her therapist or is this happening in the present?

One morning on the train, Rachel sees Megan standing on her balcony with a strange man. The two embrace and then kiss. Rachel is outraged! Her fantasies of their perfect marriage are dashed. Rachel gets off the train in the city and starts drinking and drinking and drinking.

That night, she gets off her train drunk out of her mind. She witnesses "something" in the tunnel underpass but she is knocked unconscious. Or did she just pass out? Rachel wakes up the next morning bruised and bloodied with no recollection of what happened.

A few days later, Rachel returns home where her friend Cathy (Laura Prepon) has let her live rent free since her divorce. Detective Riley (Allison Janney) are there to question Rachel. Megan has been murdered. Anna told the detectives she saw Rachel in the vicinity that night. Rachel does not remember what happened that night. Rachel denies killing Megan. Did Rachel kill Megan? Rachel doesn't know.

The remainder of The Girl on the Train revolves around Rachel trying to remember what happened that night, events that led to Rachel drinking and her divorce, the truth behind Megan and the stranger on the balcony, Megan's husband Scott (Luke Evans) becomes the prime suspect in Megan's murder after Rachel tells Detective Riley about Megan's "affair", how ex-husband Tom and new wife Anna are involved, and whether the therapist Dr. Abdic is involved.

The Girl on the Train is a confusing mess, jumbled together until nothing makes sense. The primary question is not what is going on. The whole movie revolves around how events in the past shape events in the future. Megan's flashbacks catch up with the present only to reveal something completely different. Because each individual remembers events differently, there is a fine line between what really happened and what someone thinks happened. When someone witnesses only a fraction of an event, how accurate is their description of exactly what happened? Detective Riley's investigation branches in several directions in large part because there is no actual evidence.

Haunting The Girl on the Train is Emily Blunt's haunting performance as Rachel. From the onset, Blunt's face shows that some bad things have happened to Rachel. Rachel's voice-over narration, while she idly looks out the window of the train, are the ramblings of a woman desperately trying to convince herself her life is good.

Learning Rachel is an alcoholic means what happened to her was very bad. No one wakes up one morning and suddenly has a drinking problem. The drinking problem develops over a long time.

Rachel's blackouts don't help her. She wants to do the right thing. She gets sober. But she can't leave well enough alone. She tries to help Detective Riley and Scott get to the truth but only makes matters worse for her and others.

Blunt never over acts. She is so good in the role of Rachel that Rachel becomes a sympathetic character from scene one. The audience wants to know what happened to her. In one scene, a drunk Rachel rambles on raving over how Anna could cheat on her "wonderful" husband. Blunt's shocking performance is also tender and sympathetic. On one hand, Rachel is rambling on drunk. On the other hand, Rachel's ramblings make sense. Rachel's husband cheated on her.

Rachel clearly needs help. Yet no one can truly help her because the past that she remembers didn't happen the way she remembers the past. In the end, Rachel is saved. Other lives are destroyed, possibly forever.

Director Tate Taylor's use of flashbacks seems like a cheap trick to confuse the audience. The flashbacks show that reality is not quite how we remembered it to be. Interjecting one's personal views into the lives of others opens the floodgates of misinterpretation. Nothing in The Girl on the Train makes sense until the final scene.

The ending is rather surprising and shocking and yet it reinforces the theme of blurred reality, especially when there is no physical evidence. Anna corroborates Rachel's account of events and yet both women interpret the mental state of another person. Their story satisfies the police It isn't the whole story, but it is good enough.

The Girl on the Train is a fascinating look into how different lives interact with different lives and how those different lives affect everyone differently. One person's reality is another person's fiction. Holding everything together is the haunting performance of Emily Blunt. Wonderful!