At the same time Luke was working, Duke had made his way to the library. There has been quite a few curious glances at him on the way there. Even though they were in the Red District, he was still just a 5 year old wearing ragged clothing.
When he entered the library, he was actually stopped and asked if he knew where he was going. But, because of the low staff count and the location being the Red District, this didn't happen again. After answering his question of where the blacksmith books were, he went into that direction to start reading.
12 A.M.
They both told of their experiences to each other. While Duke had actually found some books on charms at the library too, it didn't seem to interest Luke. All that he wanted to do after working all day was sleep.
Even though Luke had fallen asleep, Duke kept talking until he himself fell asleep.