Update: August 27, 2020:
Snyder has told io9 that the book has been renamed “Nocterra” to avoid confusion with other comics. “Even though the subject matter and spelling were different, we’re changing the name of our series, both out of respect to the other creators and to not cause confusion for fans,” he said.
Original story is as follows:

The book follows Valentina “Val” Riggs, a “ferryman” who transports people and goods in her heavily illuminated eighteen-wheeler. According to the synopsis, “When an old man promising sanctuary offers Val a job to drive him and his granddaughter up through the Rocky Mountains, she takes it, hoping there might be some truth to his claim. What she finds in the end, though, is something much more horrifying than any shade…”
Snyder told CBR, “‘Nocternal’ has been in my head for a long time. I was afraid of the dark as a kid, and when my own son started having similar fears, the idea just sort of came to me. What if night never ended? And what if this new darkness was scarier than anyone imagined? What if any living thing that stays in it too long is changed into something monstrous… It’s a world where survival is about staying in what little light is left.”
He added, “Tony felt like the perfect artist on both fronts. I’ve been hoping to team up with him for a long time. We’ve been friends ever since we traded places on ‘Detective Comics’ and ‘Batman’ back in 2011. I’m just a huge fan of him as an artist and a writer. Tomeu really blew me away when we worked together on ‘Justice League,’ and Deron and I have done some special issues together over the years. He’s a real artist in his lettering. So for me, this team… they’re just a group of creators I admire and am inspired by so it’s a perfect fit for ‘Nocternal,’ the first book I’ll be doing as a big return to creator-owned.”
While “Nocternal” will debut digitally and in comic book stores in 2021, a 72-page collector’s edition of the first issue, featuring the script as well as Daniel’s original black & white interior art, will be made available to Kickstarter backers in December.