Abby Mills returns to Harper's Island for the wedding celebration of her best friend, Henry Dunn, and his fiance, Trish Wellington. Abby hasn't been home in seven years, since her mother and five others were murdered by John Wakefield.

The wedding party heads out on a scavenger hunt. While out, Trish meets up with an old flame, Henry talks to the locals, and Abby runs into a friend who has been haunted by John Wakefield.