After PENINSULA, the not-as-good follow-up to his excellent TRAIN TO BUSAN, Yeon Sang-Ho has returned to the zombie genre with, I am happy to report, another solid banger.

This one kicks off in another confined space - a tower block playing host to a biotech conference. Police suspect a disgruntled scientist may be on site, planning some sort of terrorist attack and, sure enough, Seo (Koo Kyo-hwan) wastes little time before injecting the CEO of the hosting company witha virus derived from slime molds. A virus which, he claims, he has injected himself with the antidote to.

To the surprise of nobody even lightly familiar with Korean cinema and Yeon Sang-ho in particular, the virus causes victims to mutate into ravenous zombie-like creatures who rapidly infect everyone they meet. This cohort of infected is slightly different, however. For one thing, they leave splats of mucus everywhere they go, for another they will periodically enter a sort of fugue state, during which they seem to learn and 'upgrade' their abilities and knowledge.

Luckily, our plucky band of survivors includes Kwon Se-Jeong (Jun Ji-hyun) a biotech professor who figures out that the infected are using their mucus as a communications medium and rapidly evolving to solve problems, in the manner of a slime mold, and that Seo may be more connected to the infected than he has let on.

This is a superbly schlocky zombie flick that hits all the usual tropes while managing to bring something new to the genre. As well as the 'hive mind' element, the choreography makes good use of the idea that the infected are learning and copying what they see. Once a wheelchair-using character loses her chair and is carried on her brother's back, the infected start clumping together vertically in odd configurations that are genuinely unnerving to see.

Seo proves an effective villain and - as usual - maybe the real monster is... man? That may be so, but the film never forgets that the OTHER real monster is of course infected zombies, and that the OTHER other real monster is infected lab monkeys in one of the creepiest sequences you will see this year.

This still doesn't quite scale the emotional heights of TRAIN TO BUSAN but in most respects COLONY is a fine return to form.