Photo: Beckett Gladney

Rolling in the Deep, Mira Grant’s (a.k.a. Seanan McGuire) science horror novella about a documentary crew who venture into the Mariana Trench in search of a mermaid hoax, only to discover that mermaids are real and very deadly, is becoming a movie! Variety reports that Branded Pictures Entertainment will produce the adaptation, with Pet Sematary director Mary Lambert at the helm.

McGuire shared the exciting news on Twitter, including her delight at Lambert joining the project:

Sing a sweet and sailing song,

The sirens call to me:

Trust them not to guide you wrong,

Or lure you out to sea… Sing a sweet and sailing song,

Set sail and chase the tide.

The sea is deep, the waves are strong.

The depths will be your bride…https://t.co/85VUvXpB7v — Seanan McGuire (@seananmcguire) November 15, 2018

And like, these mermaids, these terrifying mermaids, they're so much just the tip of the murder iceberg, and this is so amazing, and I am so excited. — Seanan McGuire (@seananmcguire) November 15, 2018

And what does Lambert think? “Rolling in the Deep is a film led by complicated badass female characters,” she said in the official announcement. “I’ve been waiting to make a film like this my entire career. Our mermaids are not cliché sugary cartoon princesses; they will take you down if you stand in their way.”

Rolling in the Deep, which the Lovecraft Reread recently revisited, was published by Subterranean Press in 2015 and is followed by a full-length sequel, Into the Drowning Deep, from Orbit Books. The summary:

When the Imagine Network commissioned a documentary on mermaids, to be filmed from the cruise ship Atargatis, they expected what they had always received before: an assortment of eyewitness reports that proved nothing, some footage that proved even less, and the kind of ratings that only came from peddling imaginary creatures to the masses. They didn’t expect actual mermaids. They certainly didn’t expect those mermaids to have teeth. This is the story of the Atargatis, lost at sea with all hands. Some have called it a hoax; others have called it a maritime tragedy. Whatever the truth may be, it will only be found below the bathypelagic zone in the Mariana Trench…and the depths are very good at keeping secrets.

“We loved Mira’s book when we read it and immediately recognized its feature potential in a market hungry for frightening yet unique fare,” said J. Todd Harris, BPE founder and president, as well as a producer on the project. “The combination of acclaimed filmmakers Mary Lambert and Sean Hood is the perfect pairing to realize the book’s potential.”

BPE executive Marc Marcum added, “The story has elements of The Shallows, 47 Meters Down, Dead Calm, and even Alien. It is meant to be the definitive adaptation of the original mermaid myth that goes back to the dawn of civilization.”

Production is expected to take place in 2019. No word yet on release date.