John C. Reilly has become such a fixture in dumb comedies and unchallenging supporting parts, it only takes a movie as middling as Cyrus to remind us that he’s a great actor. Reilly plays John, a lonely guy who meets the sexy and sweet Molly (Marisa Tomei) at a party thrown by his ex-wife. Everything about Molly is perfect—everything except for her creepy, 20-something, soundscape-creating, live-in son Cyrus (Jonah Hill), who wants no competition for his mother’s affections. Jay and Mark Duplass shot Cyrus in the intimate, handheld, emotionally terse style of their low-budget “mumblecore” films, but all that does is draw your eye away from an intriguing but underdeveloped script that goes squishy in the end. The real appeal of Cyrus is the actors; Hill actually acts, Tomei is excellent but ultimately underused and Reilly gives his best performance in years.