And then there were six…and soon thereafter five. The countdown has very much begun for the students on Tsunojima, and if you didn't know before now that author Yukito Ayatsuji took a lot of his inspiration for the original novel from Agatha Christie's seminal 1939 novel And Then There Were None, that should be very clear from this moment on. Certainly that's in part because the countdown has begun, with Orczy's murder at the end of the first volume being discovered at the start of this one, but there's more to it than that: in Christie's novel, people are picked off in a very specific order, based not just on the “Ten Little Soldier Boys” poem (or “Ten Little [racial slurs],” depending on how old an edition you read), but also on perceptions of their guilt.

This makes one of the features of the manga not present in the original novel a particularly interesting addition to the story. While Ayatsuji's book is primarily told from a more omniscient point of view, it does occasionally delve into the minds of Conan and Ellery, but not really any of the other characters, or at least not on a meaningful level. Hiro Kiyohara's adaptation, however, allows us into Orczy's memories, most specifically her memories of Chiori, the club member who perished in a (manga-exclusive) boating accident. Chiori's death is the central force around which all other events in the novel are shaped, something volume one let us in on by not only introducing the fact that she had died during a club activity, but also that she was born on Tsunojima and that her reclusive architect father built both buildings on it – the Decagon House and the Blue Mansion, where he lived until his death with everyone else in the building. That means that there is a persistent link to Chiori, one which affects each of the club members differently. It is this link that flashbacks and point of view shifts begin to really explore in this volume as we see how important Chiori was to Orczy before her drowning.

While I would hesitate to say that the characters in the source novel aren't well written or developed, it does feel like the manga version is going the extra mile for a few of them. Specifically, we get a much better sense of Orczy as a person, and that it comes after we already know she's dead adds to the creepy melancholy of the story as a whole. Orczy, who first met Chiori in the university dining hall, was able to find the strength to come out of her shell because Chiori reached out to her; in fact, both women joined the Mystery Club in the first place because it was Chiori's idea. This certainly makes Chiori's death on a club outing more tragic, but it also shows us how great an influence she was on Orczy, while also providing her with a motive for going on the trip in the first place. While we could argue that members like Ellery went to the island as a form of murder tourism, Orczy has gone to try and feel close to her dead friend one last time. She's there to mourn, not to play murder games. That indicates that her death coming first – and happening in her sleep – is meant to show us that she bears the least guilt in Chiori's passing; she truly cared about the other woman and while she was involved in her death (simply by virtue of being present, perhaps) and therefore must die, she doesn't need to suffer – or at least not as much as some of the others by the murderer's reckoning.

The question of who the murderer is forms another link to Christie's novel, which also takes place on a remote, isolated island. Within the closed cast there, a question arises as to whether or not someone else could be on-island, picking people off, and the characters in this series aren't mystery buffs for nothing – in fact two of them are named for authors of formative locked-room stories. (Leroux, for Gaston Leroux, is the other; The Mystery of the Yellow Room is a locked-room classic.) Ellery is also well aware of the fact that Chiori's father was the sort of architect who enjoyed putting secret chambers and passages into the buildings he designs, which gives plenty of fuel to the idea that someone could, in fact, be hiding somewhere else on the island. Meanwhile over on the mainland, Shimada and Conan are asking around about Tsunojima, and Shimada mentions that Chiori's father's face was destroyed after death. That, combined with the missing gardener, could mean that if there is another person on the island, it could be Mr. Nakajima – and he'd have a pretty good reason to want the Mystery Club members dead.

There are holes in this theory, of course. The major one is that when Orczy remembers Chiori's funeral, she notes that her father wasn't there. While this could mean that he was too prostrated by grief to attend, it also could mean that he simply didn't care enough, which works against the idea that he's the killer. The young fisherman Conan talks to is also delightfully pragmatic about all the rumors about Tsunojima, deflating a lot of her budding theories and making it seem like the killer is, in fact, a club member. Not that either of our pair of mainland detectives know that there is a murderer, but Conan has clearly read enough mysteries that she's concerned that her former clubmates may not be safe.

She's not wearing that 221B jacket for nothing, nor is Ellery named after one of the greats of the fair play detective genre to be tossing out empty theories like confetti. There's something foul afoot on Tsunojima. The only question is whether our detectives have the time to figure it out.