Indie banner After Dark Films has bought Jonathan W. Stokes’ “El Gringo,” a Mexico-set action script.After Dark plans to begin production this fall and is currently out to directors. Joel Silver will exec produce. Story centers on a wounded American who plans to retire in Mexico with millions in cash. Stokes wrote and directed 2009’s “The Last Hurrah,” a comedy about college graduate students at a house party on their last night together. After Dark is producing Walter Hill’s upcoming action thriller with Sylvester Stallone as a New Orleans hitman who teams with a Gotham cop to take down the killers of their respective partners. Stokes is repped by UTA and Energy Entertainment.