Books, a lot of books. The first building was filled with a lot of books but they were protected using arrays. These arrays protected these books from decay during these long years when there was no one to take care of them.
"Hmm, looks like the arrays are basic and are only to protect the books against any damage. They worked perfectly for all these years. Let's put them all in the inventory. It's a waste of time to read them now", Chris decided and started to lot the building of its books.
As Chris was a Runesmith, he had an initial understanding of arrays and formations. As long as they weren't complicated, he was sure to dismantle them. These books don't have protection against theft, just against decay, pests, and any kind of damage that can destroy the books.