The scraping was driving Nikhil insane. Or maybe he was just imagining it. Maybe he was already insane.
He shook his head vigorously, willing the sound - imaginary or not - from his ears. Scratch, scratch, scratch, scratch. For what had to have been the thousandth time in weeks, he searched the room for its source, but once again came up empty - it was everywhere and nowhere at once, on and off and then on again for hours at a time. Scratch, scratch, scratch, scratch.
Nikhil stood and paced back and forth in his cell, hunched slightly so his head wouldn't brush the cold, hard ceiling. Perhaps his footsteps would drown out the noise, bring him some relief from this torment. But it persisted - scratch, scratch, scratch, scratch - the tiniest little scraping, reverberating off the walls until it formed the blaring soundtrack to his every thought.