In the 'Great Modron March', there is an intelligent, talking book. I have always wanted to run a series of adventures where the book is missing some pages and hires the PCs to find them.
I think the book was going to be a diary, so the entries would hint at the possible locations of each missing page. For example:
"I was in the Feywild, near the Seelie Court today when [ page missing ]."
So if the book was missing three pages, it means you would have three adventures.
That might require more planning than can be done with gnat-attention-spans, though...
(Oh! Edited to add that the final reward was that the book, when completed, would have some of the memories of the original owner, and knows the location of the owner's treasure stash, which would lead to the last adventure of the book plot...)