It’s possible that Sean Bean’s character will return for National Treasure 3, and this would be the perfect way to get the franchise’s ball rolling again. Ben Gates’ story has been at a standstill since 2007 when National Treasure 2: Book of Secrets ended with a cliffhanger that has yet to be satisfied. Though a threequel was confirmed that same year, the film has since ended up in development hell. However, original National Treasure director Jon Turteltaub has provided some intriguing updates on the project, indicating that it may still happen.

https://screenrant.com/national-treasure-3-sean-bean-ian-return-restore-franchise/