A family of five, including three young daughters, embark on a summer vacation to their Swiss cottage. However, their tranquility is disrupted when a man, Harry, who claims to have known the father, Michel, from high school, appears and becomes an unwelcome guest. Despite their initial reluctance, Harry's persistence and seemingly harmless nature eventually win them over, but it becomes clear that he is hiding a dark and sinister motive.

With a Friend Like Harry...
The story follows two former classmates, Harry and Michel, who reconnect, but Harry's growing obsession with Michel's life sets off a chain of unsettling events.