With the release of The Dark Tower finally approaching, it’s time to get acquainted with its lore. Thus—after some expository spots—Sony has released a featurette explaining just what a Gunslinger is for those who might be new to Stephen King’s universe. Specifically, it delves into Idris Elba’s Roland Deschain, the last of those whose duty it is to guard the eponymous structure. “When I started The Dark Tower, I really saw the Gunslinger as this kind of concentrated force,” King himself says. The clip also includes footage of Elba showing off the skills that the name Gunslinger implies. The Dark Tower is due out August 4.