Course Hero. "The Girl on the Train Study Guide." Course Hero. 3 Aug. 2017. Web. 13 Dec. 2018. <https://www.coursehero.com/lit/The-Girl-on-the-Train/>.
Course Hero. (2017, August 3). The Girl on the Train Study Guide. In Course Hero. Retrieved December 13, 2018, from https://www.coursehero.com/lit/The-Girl-on-the-Train/
(Course Hero, 2017)
Course Hero. "The Girl on the Train Study Guide." August 3, 2017. Accessed December 13, 2018. https://www.coursehero.com/lit/The-Girl-on-the-Train/.
Course Hero, "The Girl on the Train Study Guide," August 3, 2017, accessed December 13, 2018, https://www.coursehero.com/lit/The-Girl-on-the-Train/.
On Saturday, August 10, 2013, Rachel wakes up in Scott's bedroom. They made love the previous night, and both are regretful. Rachel notices that all traces of Megan are gone, including all the pictures. As Rachel leaves Anna is outside and runs away when she notices Rachel. At the train station Rachel remembers Anna's running away like that before.
Thinking back on how it all started, Rachel admits that she wanted to have what she believed her imaginary versions of Megan and Scott, Jess and Jason, had. She wanted to leave her own life behind and be Jess. But now, having slept with Scott and thus essentially taking Megan's place for a night, she feels repulsed. Wondering what sleeping with a virtual stranger less than a month after his wife died says about Scott, she once again has to realize that the real Scott has very little in common with the imaginary Jason.
By the same token, being Jess is not what she had imagined. Megan and Scott's relationship was not the blissful union she ascribed to Jess and Jason. Having stepped into the lives of her imaginary perfect couple, she realizes that on the one hand the reality of other people's lives is never as simple as it seems, and that on the other, it is not possible to leave one's own life behind. She cannot become Jess any more than Scott can become Jason. People are what they have become in the course of their lives. Just as Megan realizes that she must face and accept her past, so does Rachel.
When Rachel sees Anna running away from her as she steps out of Scott's house, she remembers that she ran away from her like that once before, on the day Anna moved into the house Rachel used to share with Tom. Unlike Rachel, who realizes she cannot step into Megan's life, Anna did step into Rachel's: she married Rachel's ex-husband, moved into her house, and had the baby Rachel so badly wanted. In this context, Rachel's sense of fear becomes existential. By stepping into her life, Anna has rendered Rachel superfluous.
The constant mirroring and comparisons among Megan, Rachel, and Anna suggests time and again that their lives are intertwined in more significant ways than just crossing paths on the day Megan disappeared.