Pei Jing kept the three cores steady through the tenth day. The hardest part came at the end. If he opened the lid while the pressure was still high, the rush of air could break all three pills.
The bronze float reached the last mark at the sixth morning bell. Two hundred and forty hours had passed since the first blood went in.
His pulse held at sixteen.
Pei Jing planted one boot on the soapstone and drew back his right hand. He remembered the trial pulse that had made the dampers rattle together. The forge workers called the full technique Harmonic Decoupling Palm. A pulse at the right pitch could shake a metal fitting loose without denting it. For Gui’s star-iron bronze cauldron, he tuned his Gang Qi to three thousand two hundred and forty hertz.
His palm struck the belly of the pot. Forty thousand pounds of force rang through the metal. The seals on all sixteen dampers released together.
Cold mountain air rushed in from every side. The air under the lid dropped from five hundred and twenty degrees to forty in six seconds. The pills cooled more slowly. With air reaching them from all sides, they cooled evenly and none cracked. The thirty-pound lid rose four feet on a cushion of amber steam, turned, and came down on the padded brackets behind the hearth.
