An unimpeachable mega-hit in its native Korea, Yeon Sang-ho’s horror-thriller floats a delicious premise – zombies on a train – delivered on several times over. Its pleasures are as much logistical as visceral: after a biotech leak, our hero – callow financier Seok, shepherding a young daughter towards an estranged wife – is confronted by the old Southern Rail trains problem of how to navigate entire carriages of violently enraged shufflers (one hint: luggage racks). Making his live-action debut, Yeon – who animated 2011’s memorably grim The King of Pigs – stages thumping close-quarters action, but also manages numerous deft, affecting manoeuvres with characters drawn from a cross-section of Korean society. We’re bound for an extraordinary rail-yard finale that involves seemingly half the country’s population and a living-versus-undead dust-up atop a runaway loco, but Yeon keeps us guessing until the nervy closing seconds. It’s a delayed arrival, but here, finally, is the summer blockbuster for which we’ve all been waiting.