What if your worst enemy discovered your darkest secret? At 2:00 a.m. on the morning of her 40th birthday, Sophie wakes in the darkness of her bedroom and finds a stranger watching her from the foot of the bed. The intruder hands Sophie a letter and issues an ultimatum: the message is to be opened at her forthcoming party, in front of family and friends, at exactly 8:00 p.m.
"A hidden gem!"
In the dead of night, Kate receives a phone call. Police have recovered her sister Anya's personal belongings at a remote hideaway in Mexico. Anya was last seen getting into a vehicle with a local diving instructor, who is also missing. Kate and Anya’s relationship has been complicated ever since a devastating tragedy blew their family apart, but Kate cannot believe Anya would willingly travel somewhere so isolated with a man she barely knows...would she?