It's not just hard to understand - in fact, it may be less difficult than she thinks, because of what he's been told about Those Who Came Before - it is also completely unacceptable. And he can't work out how he got here. As far as he knows, he hasn't touched any artifacts since the crystal his village had. Did the man going to New York with him have something to do with it?

"Why?" he asks, his tone tense. "For what purpose am I here?"

Because there has to be one. Doesn't there? For the last few years, at least, he has felt that what happens has had a purpose. This? He can't be here. He needs to deal with the Templars, he needs to help his people.

Isn't that what the crystal told him?