Cyrus

Directed by Jay Duplass and Mark Duplass. Starring John C Reilly, Jonah Hill, Marisa Tomei, Catherine Keener, Matt Walsh 15A cert, lim release, 91 min

THE LATEST FILM from the Duplass brothers, those key figures in the so-called mumblecore movement, wallows in a singular class of tension throughout its nicely odd 90 minutes.

Cyrusstars John C Reilly and Marisa Tomei as a couple embarking on an initially a promising relationship. After getting it together at a party, John, a shy divorcee, works up the courage to make another date with Molly. There's just one problem: Cyrus, Molly's grown son, despite smiling damply at John every time they meet, appears to view the relationship as a foul outrage of Hamletian proportions.

On the first night John stays over, the Oedipal wreck hides the older man’s shoes. Later, Cyrus invites himself to a wedding – that of John’s first wife, as it happens – and, after guzzling a vat of champagne, behaves in excruciatingly embarrassing fashion.

Shot on a flat digital medium in a particularly anonymous corner of the Los Angeles sprawl, the film boasts diligently introverted performances from Tomei and Reilly. Neither ever seems fully awake, but, if independent movies are to be believed, most citizens of southern California exist in a kind of walking coma.

The fulcrum of the film is, however, the unsettling, slippery turn by Jonah Hill in the title role. Here's where that tension comes in. By casting Hill, star of Superbadand Get Him to the Greek, the film-makers nudge the viewer into thinking that at any moment the movie is going to turn into something broader and sillier. Then again, the knowledge that we're watching something from Fox Searchlight, a faux-indie studio, suggests that the intimations of darkness might convert into all-out flesh-chewing madness.

Such tonal uncertainty is unusual in commercial cinema, and Hill is to be congratulated for sustaining an uneasy balance between mere oddness and full-blown psychosis. Cyrusis a small film, but it's an inventive one.