First-time director BEN AFFLECK moves behind the camera for the new Boston-based movie 'Gone Baby Gone' -- in theaters October 19 -- and our THEA ANDREWS is talking to him!

The compelling drama is based on the book by Mystic River writer DENNIS LEHANE and was adapted by Ben and screenwriter AARON STOCKARD. Of course, Ben landed an Academy Award for co-writing 'Good Will Hunting' with good pal MATT DAMON.

'Gone Baby Gone' is also a family affair, with Ben's younger brother CASEY AFFLECK ('The Assassination of Jesse James by the Coward Robert Ford,' 'Ocean's Thirteen') in the lead. Ben spoke highly of Casey telling ET "My brother is an exceptional actor." He also gave his cast all the credit saying "I was honored to be among them."

The film tells the story of a pair of private investigators (Casey and 'M:i:III' star MICHELLE MONAGHAN) searching for an abducted four-year-old girl in Boston's seamy underworld, where nothing is as it seems.

The film also stars MORGAN FREEMAN, AMY MADIGAN and ED HARRIS.