Seeing as Mike’s character was both a little underutilized in IT: Chapter One, as well as the fact that in the book Mike gets separate interludes in which his research into the history of Derry gets played out, the possibility for a second film that shows Mike’s research and his flashbacks to the childhood of the Losers’ Club just might work.
Another fact we’ve been privy to when it comes to IT: Chapter Two is the fact that Mike Hanlon, expert librarian and armchair historian to Derry, Maine, is going to be slightly altered for his adult form.
In particular, Mike is going to be written as a junkie, with his addiction helping him open his mind to the truth of what happened in their childhood.