Miguel Mora, who played Robin Arellano in the first film, returns in the sequel as Ernesto, Robin's brother.
Though the sequel was not based on a specific Joe Hill story, he still provided the initial concept to the filmmakers. Screenwriter C. Robert Cargill recalled, "He just said, 'A phone rings, Finney answers, and it's The Grabber calling from hell.'"
In one scene, Finn is watching a music video for the song "Subways of Your Mind" by the band FEX. The song, for years, was famous for being "The Most Mysterious Song on the Internet," as a recording of it circulated on the internet for years with no attributed artist. The search lasted several years, only to be solved in late 2024.
. There were no digital tricks used for the dream sequences as it was put together using Super 8 proper for the scenes without sound, and Super 16 for the moments that featured dialogue, which were then cut in half to be 8mm. Meaning, the moments shot on Super 16mm were framed with half the image and then expanded for even more of that grainy look-old-school, practical, classic filmmaking.
Scott Derrickson initially wasn't going to make a sequel until he received a phone call from author Joe Hill. Hill's pitch involved the Grabber calling Finn from hell, which sparked Derrickson's interest and opened up supernatural possibilities for a sequel. After being hesitant, Derrickson changed his mind after the phone call and decided to make the sequel.