Kell hears, or thinks he can hear, a voice from outside. It's muffled, the words unrecognizable, but it's accompanied by a loud thud. It's too dark for him to be able to identify the source of the sound, but it must come from the outside.

So he yells some more. Not really words any more, his throat too raw from all the shouting, and the stinging, polluted air he's breathing. Any attempts at words end in a coughing fit, that only makes him feel worse.

At least he moves closer to the side where the sounds come from. Kicking the wall doesn't help much, but at least he might get noticed better.