X and Jamie are too far away to hear them.

It's kind of a pity.

But eventually (less than a minute and a half later, if anyone's counting--she is--) they reach another stairwell.

She pauses in front of it again, listening, scenting the air.

Then she nods, just once, and slides it open very carefully. She'll hold it open for Jamie, then slip past him and continue upward until they find a door to the outside.

It shouldn't take long.

(And if worst comes to worse, they can go through the wall. It'll just be--loud.)