Fast-moving zombies are the only thing holding back South Korean horror-thriller Train to Busan from greatness. The zombies that attack cross-country train passengers during a never-explained crisis instantly change from infected humans into flesh-eating monsters, sprinting, tackling, and even dogpiling their prey.

Thankfully, writer-director Yeon Sang-ho (King of Pigs, Seoul Station) doesn’t dwell on the zombies, but rather foregrounds financial manager Seok-woo’s (Gong Yoo) struggle to bond with estranged daughter Su-an (Kim Su-an) while he accompanies her to a militarized safe haven. We’re introduced to several supporting characters, including nervous baseball player Young-guk (Choi Woo-sik), pugnacious muscle-bro Sang-hwa (Ma Dong-seok), and shy housewife Sung-kyung (Jung Yu-Mi). But these secondary figures only teach Seok-woo, an observant but lazy executive who usually delegates his day-to-day tasks to business partners and underlings, how to care for Su-an.

Yeon’s patient direction and clever plot twists make Seok-woo’s transformation from selfish antihero into brave caregiver consistently compelling. Especially riveting are scenes in which Seok-woo uses athletic tape, fire extinguishers, and cellphones to rescue Su-an from train cars full of zombies. Better still: Yeon’s creative use of an already claustrophobic setting — particularly door locks, shatter-proof windows, and luggage racks — will make you yelp at every predictably moralistic death scene.

Train to Busan won’t surprise you, but it will get under your skin.

Train to Busan

Written and directed by Yeon Sang-ho

Well Go USA

Open July 22, AMC Empire 25