Olivia Thirlby, one of my favorite up-and-coming actresses, has scored the leading role in The Darkest Hour, a sci-fi action movie from Summit and New Regency, reports Heat Vision. Chris Gorak (Right At Your Door) is directing the pic, which is being produced by Russian filmmaker Timur Bekmambetov and Tom Jacobson. The script, which Gorak and Josh Zetumer are currently revising, is set in Moscow and follows a group of Americans traveling in the city when an alien invasion occurs. Thirlby, the young actress known for supporting roles in such indies as Juno and The Wackness, plays a trust fund girl trying to survive the attack who teams up with others to try to defeat the invaders. The movie lenses this summer in Moscow, where Bekmambetov will use his own facilities for the shoot and special effects. Thirby is also filming Jack & Diane this spring.