After Ruth moves in with her boyfriend in a remote holiday park, tensions rise as she makes an unsettling discovery that lures her into a spiral of obsession.

A screenwriter does research for his new script by actually kidnapping and drowning young girls. He then places them in his "garden" of other dead girls coming back daily to check on them. One girl narrowly escapes and the other bodies are found leading to an ingenious plot to try and capture the killer.