Arthur had spent the first few hours (his watch was precision, and working) trying to get the beam to move in different fashions, and even using his lower body for leverage hurt like hell. His expression tightened slightly but he nodded in a sharp dip of his head, dirt-streaked face intent. He used his core to pull himself upright and did his best to try to brace himself, but there wasn't much in the way of leverage; even to sit up he had to use all abs and hold himself there.
"No. You do what I do too long, and it's the only way you can dream," he said, grimly, putting his hands out on the thing that trapped him. "Say when."