As high-concept adventures go, Cowboys & Aliens is a slick, efficient piece of filmmaking that delivers exactly what its title promises, and never aspires to anything more. It coasts on the rogue appeal of two leading men, Daniel Craig and Harrison Ford, whose chaps are as leathery as their furrowed brows.

If the goal of every screenwriter – for Cowboys, producers Brian Grazer and Ron Howard assembled a small army of them – is to grab our attention in the very first frame, well, mission accomplished. Here, we find a bloodied stranger, unarmed and alone in the Arizona badlands. An elaborate device, possibly alien in nature, clings to his forearm like a parasite.

Trouble finds him swiftly, in the form of three gunslingers on horseback. Rightly taking him for a fugitive and eager to claim a reward, they draw their weapons. Moments later, they lie motionless beneath the sweltering sun as our stranger, clearly not one to be trifled with, calmly makes off with their booty.

He is Jake Lonergan (Craig), an accused killer from parts unknown, his past as much a mystery to himself as to Absolution, the one-street town he makes his temporary home. It doesn’t take Jake long to run afoul of the local deputy (Keith Carradine), and Colonel Woodrow Dolarhyde (Ford), an aging war hero whose bite no longer matches his gravelly bark.

The plot, inspired by Scott Mitchell Rosenberg’s 2006 graphic novel, settles into high gear as Lonergan and Dolarhyde are thrust into a tenuous alliance. Absolution is under siege, its townsfolk systematically abducted by UFOs, and who better to rescue them than 007 and Han Solo?

Why the aliens attack is never adequately explained. They’re after our gold, we’re told, though they seem quite capable of taking it without all the pyrotechnics and air strikes. (“That’s just ridiculous,” Dolarhyde snarls, speaking for the audience. “What do they wanna do, buy something?”)

Then again, Cowboys isn’t meant to tease the imagination so much as divert the senses, which it does nicely. It’s not entirely without soul, thanks to Ford, whose gruff exterior masks a noble conscience, and a stellar cast of sympathetic supporting players, including Olivia Wilde, Sam Rockwell and Clancy Brown.

Director Jon Favreau (Iron Man) once again proves himself an astute storyteller. Lacking a hero as charismatic as Tony Stark, and saddled with a narrative lacking any discernible raison d’être – besides staging an alien invasion in the Old West – he keeps the action constant, and far more enthralling than logic alone would allow.