Nobody does it better than Keanu Reeves in “John Wick: Chapter 2,” a crackling action flick about the world’s most ruthless hit man. With Reeves returning in the impassive but ridiculously violent title role — he once killed three people with a pencil — “John Wick: Chapter 2” is a vast improvement over the uneven first film. Funny, inventive, just the right degree of implausible and packed with some of the best fight scenes to hit a screen in years, this sequel feels like the official announcement of a major new franchise.

Few would have expected that when “John Wick” arrived in theaters in 2014. Though impressively rough and visceral, its villains were bargain-basement Russians and its backdrop of a secret society of assassins — with their own currency, rules of conduct and a no-fighting zone called the Continental Hotel — felt like a rehash of “Constantine” (an excellent Reeves vehicle from 2005). The movie had its moments, but mostly felt muddled.

Not so here. “Chapter 2” embraces the secret society wholeheartedly, drawing Wick into some court intrigue as fellow hit man Santino (Riccardo Scamarcio) forces Wick out of retirement (he can’t say no; it’s an honor thing) to kill a “high-table member” of the Continental. Things go south, of course, and Wick soon finds himself targeted by every hit man on the planet, including his former friend Cassian (a convincingly steely Common).

“Chapter 2” establishes director Chad Stahelski (returning from the first film) as a top-notch action filmmaker. Just as John Woo made the double-fisted shootout his signature, and George Miller laid claim to multicar warfare, Stahelski specializes in the close-combat gunfight, in which two opponents struggle with a pistol as if it were a knife, firing bullets across and over and occasionally into each other. It’s a fresh twist on the fancy but repetitive gun-fu of the first film (though there’s plenty of that here, too).

“John Wick: Chapter 2” makes great use of locations (Manhattan’s new Oculus subway hub, for one) and of supporting actors such as Ian McShane (returning as the Continental’s no-nonsense proprietor, Winston) and Ruby Rose, who plays the mute but ferocious assassin Ares. (This is Rose’s third action film this year; somebody give her a starring role, quick.) The whole thing ends on a tantalizingly dark note that suggests an insane, near-apocalyptic Chapter 3. “Tell them,” says Wick, “I’ll kill them all.”