Now they’re happily married wives and mothers with successful careers: Zadie as a pediatric cardiologist and Emma as a trauma surgeon. Their lives are chaotic but fulfilling, until the return of a former colleague unearths a secret that one of them has been harboring.

As chief resident, Nick Xenokostas was the center of Zadie’s life — both professionally and personally — throughout a tragic chain of events during her third year of medical school. Nick’s unexpected reappearance shocks both women into taking a deeper look at the difficult choices they made. As it becomes evident that Emma must have known more than she revealed about circumstances that nearly derailed both their lives, Zadie starts to question everything she knew about her friend.

ER physician-turned author Kimmery Martin lives in Charlotte.

Softcover, 368 pages, $9.19; e-book, $12.99.