Tom Watson is the main antagonist of the 2015 drama-mystery book "The Girl on The Train", and it's 2016 film adaptation of the same name. He is the abusive ex-husband of Rachel Watson and the current husband of Anna Watson.
It is unknown how Tom met his first wife Rachael years before they were married. Tom was actually abusive towards her due to the fact she was infertile and tried in-vitro fertilization to make him happy. Tom was responsible for Rachael's drinking when he gasligted and manipulated her to alcoholic drinks and the relationship between them is troubled yet abusive.
Tom made his legal troubles when he smashed the house with golf cubs in a rage before planting false memories in Rachael's head, making her belive she was responsible behind this. Tom began having affairs with his co-workers before hia boss discovered this and fired Tom. Later, he met Anna Boyd, a real etesle agent who become his mistress.
Later Rachael discovered the affair which caused the end of their marriage. Following that, Tom and Anna are married and had a daughter named Evie. One day Anna was sleeping and ignored Evie's cries before a visiting Rachael picked up the baby and walked her outside for comfort, which lead to a false accusion of kidnapping.
The Wastons hired Megan Hipwell, a married woman with troubled a marriage who also had a tragic past (she once had a baby girl with her late brother's best friend and acceidently drowned her). She tried to have an affair with her therapist Kamal Abdic, but he redused. Megan and Tom become romanticly involved behind Anna's back.