this is just stupid, they are stupid, it was the princess herself who disappeared on her own and left her maid and the director behind, how should our mc have planned this, and from everything we know, he is a plain librarian with probably little social life considering he frequently reads books there after his work, probably also lives there, he is absolutely no assassin, has no motive, and would normally also not have had the opportunity to be even near her, not to mention drinking tea with her alone...
every other person is more suspicious than him...
and from the premise of the tower favors talent and effort, not background, plus a flourishing millenia empire I was expecting a better justice system, single corrupt elements are always a possiblity, but to torture someone like that and then without knowing anything for sure, executong on the spot, eh no