One of us knows : a thriller / Alyssa Cole.

"Years after a breakdown and a diagnosis of dissociative identity disorder derailed her historical preservationist career, Kenetria Nash and her alters have been given a second chance they can't refuse: a position as resident caretaker of a historic home. Having been dormant for years, Ken has no idea what led them to this isolated Hudson River island, but she's determined not to ruin their opportunity. Then a surprise visit from the home's conservation trust just as a Nor'easter bears down on the island disrupts her newfound life, leaving Ken trapped with a group of possibly dangerous strangers--including the man who brought her life tumbling down years earlier. When he turns up dead, Ken is the prime suspect. Caught in a web of secrets and in a race against time, Ken and her alters must band together to prove their innocence and discover the truth of Kavanaugh Island--and their own past--or they risk losing not only their future, but their life"--