Ben Affleck will make his directorial debut a family affair after casting brother CASEY in the lead.

The Afflecks are behind the movie adaptation of Mystic River writer DENNIS LEHANE's GONE BABY GONE, which the elder brother has adapted for the big screen.

In the film, Casey Affleck will play one of two Massachusetts private investigators on the hunt for an abducted four-year-old child.

Ben Affleck admits the low-budget project, which will start shooting this summer (06), is already terrifying him.

He says, "The budget is excruciatingly tight, I am regularly abused and I expect to be fired sometime before we shoot."