There was nothing beyond the hallway and that, perhaps, was the unnerving thing. It was far too quiet; their foes couldn't all be gathered in one place, could they? It didn't make sense. The sound, too, hadn't gone away. As Elissa shook her head to indicate they were alone, she stepped out into the adjoining hallway for another look.

The sound was louder now and she finally discovered where it was coming from. She turned to Duncan and nodded her head to one of the air vents in the walls.