Screenwriter C. Robert Cargill, who wrote the script for 2016’s Doctor Strange, is returning alongside director Scott Derrickson to write the script for the 2021 sequel. Sources confirmed this morning that Cargill, who recently hinted that he was working on a secret project, will produce a script that Marvel Studios will review before finalizing a deal.

Derrickson himself recently signed a deal to return to helm the sequel. Production on the untitled film is expected to begin in the spring of 2020 with the studio targeting a release date of May7, 2021.

Cargill and Derrickson have collaborated on several projects over the years, including Sinister and Sinister 2, and have previously revealed they had put a good deal of thought into planning the Doctor Strange sequel. In a 2018 Q&A i with Movie Web, Cargill had the following to say about what to expect in the follow-up:

Nightmare will be the villain. Me and Scott have not laid the groundwork for it but what I can say is that I have a feeling that whatever Nightmare is involved with, Baron Mordo, being somebody who considers himself the defender of natural law will have something to do with it.

For those of you who have ever read the comics, you know that Baron Mordo has a very particular arc, and that’s something we discussed with Chiwetel while working on the first movie. And part of the reason Chiwetel wanted to play Mordo was because he has a definitive ending as a character and it’s such a fascinating ending. And I do know that whether we’re attached or not, that Marvel plans on working towards that ending and fully realizing Mordo as more than just a cardboard cutout villain, but actually taking him to kind of Loki levels of awesomeness. That’s the goal with him.

Derrickson originally intended for Nightmare to be the villain of Doctor Strange before being convinced by Kevin Feige that such a character might require a great deal of exposition for an film which already featured quite a bit as it introduced the idea of other dimensions.

Cargill was contacted in reference to the story and gave no comment.