B
These people might know more; and information never hurt anyone. It's their choice what to do with it. If they choose to risk their lives, well, it's better that they know what they're getting into rather than stumbling around blindly.
Plus we need to meet more people so we can figure out whom we need to give The Box to, anyways.
Edit: and now that I think about it, Mizuchi Kagemaru sounds... suspicious. Very suspicious. Demonic first name, surname that sounds more like a given name... We must investigate!
--
Oh, a big machine with flashy lights. A big machine like that has me written all over it. Well, okay, it doesn't. But give me time... and a crayon --11th Doctor