Roughly On Par with the Cakemaker of Kiev

He was trapped. There was no where to move, nowhere to go, and he could feel the air getting thinner. Each breath was harder to draw than the last and his lungs burned with the effort of extracting what little air was left. The phone glowed blue in his hand, Parker's voice telling him he could do it, he could make it, that she needed him, and Hardison wanted to hold on for her, to prove he could do it, hell, just to see her again and make sure that there wasn't new pain in her eyes, but he knew that they weren't going to arrive in time. He strained his ears to hear the sound of the ambulance, the sound he knew he should make out by now, but they weren't close enough, he couldn't hear anything, not even Parker's voice anymore and the phone's glow died, leaving him trapped in darkness, the scent of the rose he'd been buried with and the varnish they used on the casker mixing in his nostrils and making him ill.

Or maybe that was just knowing he was going to die, all alone, in this tiny box he could never get out of by himself...

Deeply asleep and still trapped inside his nightmare, Hardison thrashed about, whimpering in fear, hot tears sliding down his cheeks.

Coffin nightmares were the worst.

[For the two there with him. Obviously]