Fantasy author George R.R. Martin has hints at a secret new project he is working on with “Game of Thrones” actress Maisie Williams, which has interested fans of the famous TV show.

Martin recently wrote on his blog that he met Williams in London over pizza and pasta, but he omitted the specifics. His writing only said, “It could be so much fun,” without explaining how they might work together.

Williams, who played Arya Stark on the eight-season HBO show, hasn’t spoken publicly about the meeting. Fans and reviewers alike loved how her character changed from the daughter of a nobleman to a skilled killer.

The possible project comes up as things are still happening in HBO’s Game of Thrones. Casey Bloys, who runs HBO’s programming, said the bond with Martin was complicated but important. Bloys said, “He’s very important to me and us.” She compared...