“Alternate history hippo western” isn’t a phrase you’re going to bust out every day, but there’s no denying its power. It says so much in four words. For many writers, a story classified as such could probably get off the ground based on the sheer novelty of the premise (which is, like the best one, based on historical fact)—what if the United States government imported hippos to farm as meat in the late 1800s, and the whole operation went south?

But Sarah Gailey is not like other writers. In River of Teeth, her debut novella, what could have been a relatively entertaining romp through the swamps of what might have been—where hippopotami breed unchecked, ravaging the southeastern U.S.—is instead an adrenaline-charged, violent, often romantic story about building a life for yourself, trying to outpace your past, and hanging onto the things that bring you joy, even when they also deliver pain.

Y’see, Winslow Houndstooth, mercenary and hop wrangler, is on a mission—and he’s going to need a damned fine crew to pull it off. With feral hippos occupying a dam in the Mississippi, Winslow has been hired by the federal government to move in with a team of hops (that’s hippos to you me, friend) and corral the ferals through a gate and into the Gulf, where they won’t be the USA’s problem anymore. Aiding Houndstooth are Regina Archambault, or Archie to you, monsieur, a con woman with deft fingers and a quick mind; Hero Shacklesbury, a demolitions expert and poison connoisseur, whose speed and smarts can’t match the power of their noble heart; Cal Hotchkiss, a gambler with a dark past and a draw so quick, you’d blink and miss it; and Miss Adelia Reyes, who turns everything she touches into a weapon, and whose every move has meaning behind it. Together on their hippos, guns loaded for trouble, Houndstooth and his crew have to face down a river full of feral teeth and a crime boss who’d sooner see them at the bottom of the Mississippi, and find vengeance and success both, or die trying.

Where to even begin? I knew Sarah Gailey voice from her short fiction, which is always fresh and new and fun and terrifying. I was curious to see what a longer piece from her would look like, and River of Teeth doesn’t disappoint. It is fun from start to finish, with real stakes, an outlandish premise turned into a real world, populated by real people. Her characters wander into the hop posse fully formed, shaped by misfortunes of their pasts, sins they’d rather forget, and hazy hopes for the future. Piloting their beloved hops (each with their own spectacular name and disposition), Houndstooth and his crew are frequently at odds, and the care they show for each other, and the vitriol between them, only grows more pronounced as the dung hits the fan.

As alt-history premises go, this one requires a lot of buy-n from readers, but Gailey takes the hop by the reins and expertly leads readers through a weird, wonderful alternate timeline where hippos aren’t the strangest thing you’ll encounter. In this western-flavored world, the protagonists are not all heterosexual, the women are not all thin, the people are not all white, and conforming to the binary is an afterthought (there are wild hippos running around, after all). This is more than a rollicking book of gunslingers riding hippos into danger; it is also a triumph for identities rarely encountered in westerns, an examination of the danger of living with a heart full of hate, and a treatise on how unity makes us stronger. No matter what happens, you take care of the hop under you; she’ll get you out of there alive, that’s a fact.

It’s in the subtle moments where Gailey truly shines; that she manages moments of subtlety in an alternate history hippo western at all is remarkable indeed. In these moments, character and action entwine in perfect ways: Archie conning her way through a town, deftly snatching purses and trading personalities for any given moment. Hero and Winslow sharing a quiet moment on the trail, their eyes catching, feeling the breathless potential that exists between two people enamored with one another. The cool, cruel confidence of Adelia Reyes. Oh, and the somber reality of living in a world where an animal the size of a small tank can drag you underwater without a moment’s notice. This is no silly book. Gailey paints a hard world; though if some of the rules have changed, there is still joy, and laughter, and love to be shared, even in the darkest hours, and those are things worth fighting for.

River of Teeth is available March 23.

Editor’s note: Sarah Gailey is a regular contributor to the B&N Sci-Fi & Fantasy Blog.