Marvel’s upcoming Doctor Strange sequel is now without a director. Scott Derrickson announced he will no longer direct the film, titled Doctor Strange in the Multiverse of Madness, in a tweet Thursday, stating he left the role due to “creative differences.” He will, however, remain an executive producer.

Marvel and I have mutually agreed to part ways on Doctor Strange: In the Multiverse of Madness due to creative differences. I am thankful for our collaboration and will remain on as EP.

— N O S ⋊ Ɔ I ᴚ ᴚ Ǝ ᗡ ⊥ ⊥ O Ɔ S (@scottderrickson) January 10, 2020

Derrickson previously directed the first Doctor Strange film, as well as horror flicks Sinister and The Exorcism of Emily Rose. Marvel Studios’ Kevin Feige first revealed the sequel’s title and premise at Comic-Con in July, stating it would be the first “scary” MCU film. Considering Derrickson’s background in the horror genre, there is much speculation as to what creative differences led to his departure.

Marvel additionally released a statement concerning Derrickson’s departure, confirming his exit by stating they “amicably parted ways … due to creative differences,” and “remain grateful to Scott for his contributions to the MCU.” Doctor Strange in the Multiverse of Madness will see Benedict Cumberbatch return in the title role, and is set for release in May 2021.