When Zheng woke in the morning, he had moved past hopelessness. There was an iron will inside him, and it refused to accept the loss of his humanity. He would fight for it, cure or no cure, and if need be he would fight to the death. As for his father, just thinking about him made Zheng unbearably sad—so he resolved never to think of him again.

He gathered himself up and started to walk away.

“Wait!” his father said. “Please stay and join me. We’ll be islands together, you and me—a little archipelago!—and we’ll always have each other’s company. It’s fate, son!”

“It’s not fate,” Zheng said bitterly. “You made a choice.” And he marched off into the jungle.

His father didn’t try and stop him, though he easily could have. A sorrowful moan rose up from his cave mouth, along with waves of hot breath that swept across the island. As he wept, the boughs of trees shivered and shook, releasing a soft rain of rubies from their branches. Zheng, pausing here and there to scoop them up, filled his pockets, and by the time he’d reached the cove and rejoined his ship, he’d collected enough of his father’s tears to pay all his men’s salaries and fill his empty coffers back home.

His men cheered when they saw him, having thought him killed by jaguars, and on his order they reeled up their anchor and set sail for Tianjin.

“What about your father?” his first mate asked, taking Zheng aside to speak privately.

“I’m satisfied that he’s dead,” Zheng replied tersely, and the mate nodded and asked no more about it.

Even as Cocobolo receded into the distance behind them, Zheng could still hear his father weeping. Fighting a powerful swell of regret, he stood at the bow and refused to look back.

For a day and a night, a pod of minke whales rode the Improbable’s wake, singing to him.

Don’t go.

Don’t go.

You are Cocobolo’s son.

He plugged his ears and did his best to ignore them.

During the long voyage home, Zheng became obsessed with suppressing the transformation that was happening to him. He shaved his feet and trimmed the seaweed growing from his armpits. His skin was nearly always dusted with the fine, powdery sand that his pores exuded, so he took to wearing high collars and long sleeves, and bathed every morning in seawater.

The day he arrived home, even before going to see his wife, Zheng went to his surgeon. He instructed the man to do anything necessary to halt his transformation. The surgeon gave Zheng a powerful sleeping draught, and when Zheng awoke he found that his armpits had been filled with sticky tar, his skin covered in glue to stop up his pores, and his feet amputated and replaced with wooden ones. Zheng regarded himself in a mirror and was filled with revulsion. He looked bizarre. Still, he was grimly optimistic that the sacrifice he’d made had saved his humanity, and he paid the doctor and hobbled home on his new wooden feet.