Thief: The Dark Project is an excellent game, which could be converted to Mount & Blade. Last week, I started working on this mod. Note that it won't slow down the progress of Song of Taliesin - I'm just doing it to take a break from historical things. Thief: The Dark Project won't be a big mod, but after completing my another project, I may decide to expand it. You'll be able to visit the City in Mount & Blade....
...In next quests, you'll visit other places known from Thief: Lord Bafford's Manor, famous Haunted Cathedral (with zombies and haunts), the Lost City and completely new ones!