The horror-tinged spin-off was announced last month following the record-breaking success of Aquaman. Talking to The Hollywood Reporter, Safran explained that the idea of The Trench came from the "early concept art days" on Aquaman.
"Then, when audiences embraced it in the movie itself the way they did, particularly that ant farm shot where the camera follows the Trench [creatures] following Arthur and Mera down into the deep, we just knew that we had something very special there and we knew what that movie should be," he continued.
"And consequently, I suspect that that's one that will come out significantly before Aquaman 2."
Safran also confirmed that Arthur Curry (Jason Momoa) and Mera (Amber Heard) won't appear in the spin-off. What's more, it won't be a prequel, but will be set after Aquaman takes place.
The four-year gap between Aquaman and its sequel is unusual given the first movie's success, but Safran said that Warner Bros did not pressure them to move faster: "You don't want to do it fast. You just want to do it right.
"We've definitely taken a page from our Conjuring playbook, which is, you've got the mothership, which is Aquaman, but there are so many great stories to tell within that universe of itself, that Atlantean universe."
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