Will had refastened his thumb and ankle cuffs after Malcolm had administered the antidote. Slowly, carefully, Bacari stretched his bound hands down behind his back until he was touching the heel of his drawn-up right boot. He twisted the heel and there was a faint click as a small sharp blade shot out of a recess there. Gently, he began to saw the rawhide thong between the two cuffs up and down along the razor edge. The blade was short and several times the rawhide slipped away from it. Once, he gritted his teeth as he accidentally cut himself. But after half a minute’s silent, steady work, the thong parted and his hands were free.
He waited several minutes before his next move, making sure that he had made no sound or movement to alert Horace. But the broad-shouldered figure remained still, head hunched forward and shoulders rising rhythmically with his breathing.
Bacari brought his hands round to the front and drew his knees up under his chin so that he could reach the ankle cuffs that bound him. He felt around in the dark until he found the release knot and twisted it. Instantly, the pressure on his ankles faded as the two loops widened. He slipped the twin loops over his feet, then carefully stripped the severed cuffs from his wrists as well. Now he was free.
But still he waited, allowing circulation to return to his limbs, mentally rehearsing his next sequence of actions.

Halt's Peril, Chapter 40