Seanan McGuire is so prolific a writer that following her career comprehensively would probably be a full-time job in and of itself. I’m a committed fan of her Toby Daye series, but I’m less committed to her other works; I’ve read some of the Newsflesh books but none of her other Mira Grant books. This one, about killer mermaids, is apparently a sequel to an earlier novella, but I can attest that you can read it independently.

In a near-future 2022, infotainment TV network Imagine puts up quite a lot of money to fund another trip to the site where its research vessel the Atargatis was lost with all hands, possibly at the hands of mermaids. A motley crew of people with their own angles join the cruise, from maverick “sirenologist” Dr. Jillian Toth and her estranged husband, corporate shill Theo Blackwell, to grad student Tori, whose sister Anne died on the previous cruise doing a job now held by one Olivia Sanderson, who finds that social interaction is often better mediated by a video camera. There’s also a trio of sisters, two of whom are twins, two of whom hold PhDs, and two of whom are deaf, all of whom I quite liked. It’s a tribute to the book that I only realized about halfway through that with the exceptions of Theo and Tori’s lab partner Luis, almost all of the main characters in the novel are women. All different women. Pretty cool.

Grant is really good at writing suspense, and she clearly did a lot of research into marine science to make the mermaids fit believably into what we know about the oceans in real life. I read the book in my characteristic fashion, skimming in chunks to get to the end, and then went back to the beginning to read the whole thing linearly; that’s when the book’s flaws became more apparent. Though you don’t notice it the first time through so much, when you’re on the edge of your seat to learn which of the characters, if any, will survive and just what is the deal with the mermaids, biologically speaking, the whole thing is somewhat overlong and overwritten, and the middle of the book sags. All of these problems are connected: Grant indulges a little too much in portentous phrasing that is trying to be ominous but too often shades into cliché, and she’s a little too into telling rather than showing some crucial character perspectives. The lull in the middle would have been much less of a lull with a more active red pen in hand, and I would have had less time to realize that Grant’s views on evolution maybe don’t quite fit with what Darwin actually tells us about evolution, which is that it’s a process with no pre-determined goal or endpoint, and that extinction is the fate of all species.

That being said, these concerns disappear in the ending sequence, which is a wild ride that ends on an oddly quiet note. I wouldn’t be surprised if there’s a sequel, and I’m invested enough in the characters that I would be very interested to read it, as well as Grant’s future novels that don’t involve voluntarily ingesting genetically engineered tapeworms.