The Perfect Stranger by Megan Miranda

What happens when your best friend becomes your worst nightmare…

Having reached a dead end in Boston, failed journalist Leah Stevens needs a change. When she runs into an old friend, Emmy Grey, who is moving to rural Pennsylvania, Leah decides to join her. But their fresh start is quickly threatened when a woman with an eerie resemblance to Leah is assaulted by the lake, and Emmy disappears days later.

Determined to find Emmy, Leah helps Detective Kyle Donovan to investigate her friend’s life for clues. But with no friends, family or digital footprint, the police begin to suspect that there is no Emmy Grey. Forced to question her version of reality and to save herself, Leah must uncover the truth – no matter how dark or terrible it may be…