The currently untitled Walter Hill / Sylvester Stallone adaptation of French comics series Bullet to the Head is quickly filling out its cast. Following news of Sung Kang and Jason Momoa, the project formerly known as Headshot has just gained Christian Slater, Holt McCallany and Adewale Akkinuoye-Agbaje.

McCallany - recently seen in The Losers and A Perfect Getaway and on TV in Lights Out - will play a cop partnered with Kang, while Slater is "a handler who acts as a middleman". A handler of what? A middleman between whom and whom? Variety's story is not big on specifics.

And despite previous reports that Jason Momoa would be playing the villain Keegan, it looks like he's just a villain, since Akkinuoye-Agbaje (Lost, Oz, The Killer Elite, The Thing) is apparently the principal bad guy: "a powerful attorney trying to cover up his scam to exploit poor neighbourhoods that have been ravaged by Hurricane Katrina".

That ought to give you a reasonable clue that the film is set in New Orleans. As previously reported, it's about a cop (Kang) and a hitman (Stallone) who join forces to take down their common enemy, and is Hill's first cinematic outing since 2002.

Sarah Shahi is also aboard, playing Stallone's daughter, and shooting starts like now in Louisiana,