The day Adam Dunne's girlfriend, Sarah, fails to return from business trip to Barcelona, his life begins to fall apart. Days later, the arrival of her passport and a note that reads, "I'm sorry – S," sets off real alarm bells. Adam is puzzled when he connects Sarah to a cruise ship called The Celebrate, and to a woman who disappeared in eerily similar circumstances. Adam must try to outwit a predator who seems to have found the perfect hunting ground...