X pauses for a moment, scenting the air and listening.

Babs' count is correct.

The walking man -- probably the one doing rounds -- is making his way toward X's position.

She breaks left, avoiding the front desk and passing by the door to the security office.

Still listening for movement in the office and in the corridor, she crouches down, nudging a flashbang under a nearby radiator.

It might be useful later.

She picks up her pace on the way to the stairwell, turning a corner just after the door to the security office opens.