Black Mass, Johnny Depp, Whitey BulgerThe first trailer for "Black Mass," the story of notorious South Boston gangster Whitey Bulger, features a stunning transformation from Johnny Depp, who plays the mob boss with such terrifying conviction that it's hard to look the character in the eye.

The clip begins innocently enough, as Whitey sits down for a delicious steak dinner with some pals. He raves about the meal, asking about the marinade, which is deemed a "family secret." But Bulger keeps pushing, until finally his friend gives up the recipe, and that's when the pleasant conversation turns deadly serious.

Depp dives into a monologue about the importance of keeping secrets, and how easily -- like the recipe -- they can be given up (and he could be sent to prison), which plays over a montage of some of his worst misdeeds. In real life, Bulger was sentenced to two consecutive life terms on charges of racketeering, money laundering, and weapons possession, and there's plenty of that on display in the trailer, all narrated by Depp-as-Bulger in a creepy, haunting performance that's certain to turn some heads come awards season.

"Black Mass" also stars Joel Edgerton, Benedict Cumberbatch, Kevin Bacon, Jesse Plemons, Adam Scott, Peter Sarsgaard, Dakota Johnson, and Juno Temple. It's due in theaters on September 18.
Black Mass - Trailer No. 1