The A.V. Club
Ignore the dark and stormy night, the tinkle of ominous music, and the whole “directed by Eli Roth” part, and Knock Knock could momentarily pass for a star-powered porno. Its setup is pure after-hours Cinemax: Stuck home working on Father’s Day while his wife and children are on a sun-and-fun vacation, architect Evan (Keanu Reeves) gets an unexpected late-night visit. Standing at his front door, scantily clad and soaking wet, are Genesis (Lorenza Izzo) and Bel (Ana De Armas), two flirty young women of indeterminate age. Stranded on the outskirts of Los Angeles without a working phone, these damsels in distress talk their way into Evan’s swanky modern home, where the conversation turns to the appeal of older men, the pleasures of three-ways, and the impossibility of monogamy. Poor Evan doesn’t stand a chance. If only someone could tell him the genre of the movie he’s unwittingly starring in.