This is the story of how my parents split me in two, and how I ultimately put myself back together...On the eve of Marin's birthday, her parents tell her they're getting divorced - or, in a parallel universe, they don't tell her anything at all. This defining moment, along with Marin's subsequent choices, turn her into polar ends of herself and drastically affect the relationships she has with her two best friends, her mom, and soccer player Sam Hanson. The possibilities of 'what could have been' play out in alternating scenarios throughout the book.If Marin can't make it into Wash U and get away from her suffocating mother, she just might self-implode. She's determined that nothing will stop her, but then she can't seem to say no to what everyone else wants - or yes to Sam, seeing as her best friend Hannah wants him too. Things that this Marin puts up with - a narcissistic mother and a buoyant yet selfish best friend - the other never would. But then, the other can't stop fighting long enough to get who or what she wants. Instead, she marks a path through life that nearly alienates her best friend Whitney and the boy from work she won't let herself be distracted by, because distractions like Sam Hanson won't get her into dance school and away from her mom.One moment may have changed the trajectory of her future, but if Marin can't find her way back to herself, she'll not only lose the boy and her best friends, but also the future she's worked so hard for.IN ONE LIFE AND OUT ANOTHER will appeal to fans of E.Lockhart, Brenna Yovanoff, and Kristin Dwyer, as well as readers who enjoyed the SLIDING DOOR premise of MAYBE IN ANOTHER LIFE by Taylor Jenkins Reid or THE MIDNIGHT LIBRARY by Matt Haig. Told in alternating chapters, this story asks if the person changes the life, or if the life changes the person.