The phrase "directed by Ben Affleck" might not be the most inspiring string of words in American cinema, but with the release of Gone Baby Gone, Affleck's directorial debut, people might be challenged to reevaluate their perceptions of Mr. Gigli.

Gone Baby Gone is based on a novel by Dennis Lehane, who also wrote Mystic River, and similarities abound between the two films: There's a child abduction, a strong focus on Boston regionalisms, and amateur private dick-style investigations. But while Clint Eastwood's Mystic River felt tough in a very polished, Oscar-baity way, Affleck's film is grittier than sandpaper, and feels, at times, like little we've ever seen in a mainstream film (thanks in no small part to the casting of countless down-and-out South Boston regulars rather than SAG extras).

Gone Baby Gone is a classic whodunit: A four-year-old disappears one night from a squalid home, and her coarse, druggy mother (an excellent Amy Ryan) doesn't even seem to care. The young girl's aunt hires semi-pro sleuths Patrick and Angie (Casey Affleck and Michelle Monaghan) to investigate, and even though it's way out of their league, they take the case and, of course, unravel secrets and mysteries that go way beyond the missing girl. Ed Harris is typically fantastic as the detective who grudgingly helps the junior investigators along, and Morgan Freeman is typically ho-hum as the classy, restrained chief of police.

Unfortunately, the pacing stutters and drags throughout the film, and the plot is marred by an ending so preposterous that even Scooby-Doo's writers would have deemed it ridiculous. While the art direction, casting, and a good deal of the action are top-notch, there's not much you can do when the resolution of your big mystery provokes unintentional guffaws.