[ Can't use? His brows furrow. ]

It opens a large building. [ He corrects. ] It took me a week to find it but the inscription on the door matched the one on the key.

[ So, he used it and it opened. He's been exploring the inside ever since. With the amount of books in the library, he'd be happy to spend days locked inside, a sentiment that quickly snuffs out with his last question. ]

The one from the other timeline. [ His answers in a neutral tone, eyes shifting away from him. ] Before you, Dean and Jack arrived.