Readers: Need help - name that new fiction title

I’m trying to remember the name of a new novel (published sometime in the past six months). As best as I can recall from the reviews, the plot involves an architect visiting an old friend in Europe to help renovate a castle. I believe that a dungeon is also involved, although that may just be wishful thinking.

I remember thinking at the time that it would be a great gift for a friend, and now of course I am completely drawing a blank at the name.

Any help would be appreciated.

Thanks, plynck