[Bigby thinks on an answer for all of three seconds. It seems pretty obvious, he thinks, though let's face it — in a place like this, just because the answer looks straightforward doesn't mean it is.]

...Probably that it needs a password. Who knows what that is.

[He wants to run his hand against his chin as he usually tends to do when he's thinking, but given its current state, it's probably for the best that it stays far away from his face. Instead, he wipes his hands on his knees, making the light blue fabric go muddy as he smears blood into it.]

Maybe it's something we can find nearby. They wouldn't tell us that much if they didn't want us to figure it out. [As he straightens up, he reaches into his pocket to pull out a few folded snapshots that he offers to Teddy.] I found these in a file cabinet a few rooms back. I don't know if they'll help any, but they had red marker on them that looked and reacted the same way the ones we found before did, except this time they...changed. Right here.

[He points to the cross on the right corner of one.]

That wasn't there when I found them.