A Separation by Katie Kitamura
From Penguin Random House:
A young woman has agreed with her faithless husband: it’s time for them to separate. For the moment it’s a private matter, a secret between the two of them. As she begins her new life, she gets word that Christopher has gone missing in a remote region in the rugged south of Greece; she reluctantly agrees to go look for him, still keeping their split to herself. In her heart, she’s not even sure if she wants to find him. As her search comes to a shocking breaking point, she discovers she understands less than she thought she did about her relationship and the man she used to love.
A searing, suspenseful story of intimacy and infidelity, A Separation lays bare what divides us from the inner lives of others. With exquisitely cool precision, Katie Kitamura propels us into the experience of a woman on edge, with a fiercely mesmerizing story to tell.