The Cost of Freedom. Chapter 3.
Jacob gritted his teeth as a whip slashed across his back.
"No lagging, slave!'
He bent and pulled another rock from the pile in front of him. Straightening up, he walked as fast as he could with it to an ever-growing rock wall. He placed his stone carefully into a space in the wall and plastered it in with clay. He paused for a moment to wipe sweat from his eyes, and was rewarded by another whip slash on his back.
"No stoppin'! Back to work!"