Thirty Years Ago On a camping trip by a remote lake, the Mercer family enjoyed the vacation of a lifetime - until a violent tragedy forced them to make a decision that would haunt them for ever. This Summer When the younger Mercers learn their father is dying, the family reunites at the lake, seeking a second chance to put their lives back together. But something is waiting . . . Four Days of Hell Also arriving at the lake are estranged son Raymond Mercer and an alluring stranger, Megan, both ignorant of the family's secrets. Within hours, they are all trapped in a relentless nightmare and fighting for their lives. Some places are better left. Some secrets are better forgotten. Some people are better dead.