Knock Knock, by contrast, is debilitatingly inert. The torture gets worse and worse, and we care less and less. I’m still waiting for Eli Roth to make a good movie. But for the first thirty or forty minutes of Knock Knock, I thought maybe this was the one.It starts off well, with a camera gliding over the Hollywood hills and locating the well-appointed, sheltered home of forty-something architect Evan Webber (Keanu Reeves) and his artist wife Karen (Ignacia Allamand).or a while, Knock Knock is content to watch the playfully tense give-and-take between Evan and the girls as they try to sidle up to him. Curious inquiries turn into flattery, flattery turns into light physical contact, light physical contact turns into rubbing up and erstwhile embraces.