How does the world end? For the four heroines of School-Live!'s zombie/moe mashup, it ends not with the zombie apocalypse, but with the threat of a simple mistake and a few secrets that perhaps should never have been kept. After rescuing underclassman Miki from the mall in volume three, volume four finds the School Living Club back in their high school hide-out, and Miki almost immediately notices that there's something off about one of her saviors in particular. Yuki's delusions that the school is functional as normal and that Megu-nee remains with them are something we as readers and Yuri and Kurumi as characters are accustomed to, and we understand both what triggered them and why she's allowed to continue with them, but Miki is in the dark. As far as she can tell, she's traded one bad situation for another – she may be in a place with more supplies and no longer alone, but Yuki's inability to cope with the situation at hand reads as dangerous to her. How can they survive if one of their number refuses to truly grasp the severity of the situation?

If there could be said to be a theme to this fourth volume, it would be the threat of one small mistake. In part this is because our main point-of-view character is Miki, and we know from the last book that she values safety above all else – she may have been slowly fading away in that mall, but she was in little danger of being turned into a zombie, and she was content to stay behind when her friend Kei decided to leave and live rather than stay and die of safety. In Miki's eyes, Yuki's refusal to accept the fact that the old world has, for all intents and purposes, ended, is a sign of danger, because she can't be trusted to follow the safety protocols if she doesn't truly grasp what's going on. While Yuri and Kurumi see Yuki as their light in the dark who keeps them enjoying things as much as they possibly can, Miki sees her as a threat.

That attitude is nicely contrasted with the actual events of the volume's end. Viewers of the anime will know where things are headed at this point, but the story is handled fairly differently leading up to it, with many more clues dropped before the actual moment hits. One of the biggest ones is when Yuri and Kurumi tell Miki about Yuki's early ill-fated attempt to bring a dog into the fold. Where Taromaru was a major character in the animated version of the story, here he serves as an awful warning, showing up before the loss of Megu-nee and playing only a brief role that is over in a matter of pages. What's important about his character is not that he exists, but that after he is gone he attempts to come back: he is driven by the same memory impulses that keep the students at school – it is somewhere he is supposed to be. This serves both as a confirmation of that previous assumption about the other students – it was mentioned but not solidified previously – and also as foreshadowing for what will happen at the book's conclusion. Megu-nee may not have read the file that Miki discovers, but her top priority was the safety of her remaining students. Wouldn't that make it her reanimated corpse's driving force?

The file Miki finds is almost as chilling as the reality surrounding the girls. It is an emergency manual for teachers about what to do if there is an “outbreak.” While the condition is never named, and parts of the file are redacted in the version reproduced at the end of the volume, it is clear that there's a reason the girls were able to make such a viable home in the school. Someone knew what was coming and kept it secret from the world at large, with five places named in the manual as shelters. The slim number indicates that this pandemic was the expected outcome and that there would be minimal survivors…and it also points to the fact that there are likely other survivors at a university, two military bases, and a hospital. The booklet also mentions medical supplies and potential cures for different strains of the illness, which is an increasingly important detail.

The outbreak is beginning to take its toll on more than just Yuki. We see Yuri growing more strained in her reactions to Miki and her facial expression while Kurumi has become too confident in her shovel and careless as a result. Miki's fear may be the biggest asset the girls currently have in terms of their survival, but none of them realize that yet. Sadoru Chiba's art enhances all of these ideas with relative subtlety in facial expressions and body language, the gruesome details of the zombie apocalypse kept to a minimum to ensure that they are all the more horrible when you do see them. This artistic contrast is part of what makes the series as a whole and this volume in particular work so well, especially since with Miki's being the dominant point of view we don't see the school through Yuki's altered eyes this time.

It would be easy to brush this series off as over-rated and just another attempt to make the zombie story fresh again. This volume confirms that it really is as good as all of its hype makes it out to be as it slowly builds a picture of what's really going on. Things can feel aggressively cutesy at times, but that nearly always gets turned on its head, making this one of the most interesting horror manga currently being published. The focus is on the survivors, not the fight against the undead, and that may be what really sets this apart in its crowded genre.