Hearing a whisper of something, Riel points it out to Grryth, who's sharp hearing is able to discern the sound of a warforged, quickly running, from deep within the cavern.
[sblock=Perception 15 (Grryth auto passes this check)]
Now that the sound is obvious, it reminds you of chunks of metal, rapidly falling on the ground. Listening to the timing of the echoes, you are able to tell that the foot steps are getting closer, not farther away. There is also something else in the echoes that makes you curious about the approaching warforged: the sound of several glass items jingling together.
[sblock=Dungeoneering 20] With your experience in underground locations, you are able to determine that the warforged will reach your current location in roughly 18 seconds (three rounds). [/sblock]
[/sblock]