Huygens had no choice but to comply. If what Spaen knew about him became public, he would be ruined anyway. He resigned his professorship and closed his clinic, over the protests of his family and colleagues. Afraid of losing their love and respect, he let them think he’d developed a sudden wanderlust. On the cold, bleak day of his departure, he waved from the ship’s deck at the rapidly diminishing figures of his wife and son.

“I’ll be back soon,” he called. Somehow he would break Spaen’s hold on him.

Life at sea was worse than Huygens could have imagined: storms, pirates, rotten food, disease; the constant threat of mutiny; countless accidents that maimed and killed sailors; frequent military skirmishes. Yet Jan Spaen thrived on all forms of danger—including the company of men who served him against their will. Day after day, Huygens endured his jovial conversation at mealtimes, seething with bitter resentment. Two years later, a Dutch traveler brought him the news that Judith had died in an epidemic. Pieter, his cherished, mentally deficient son, was put into Leyden’s squalid insane asylum and died soon afterward. These were tragedies Huygens might have prevented, if only he’d been there! His hatred for Spaen grew. By changing his ways and healing the afflicted, hadn’t he atoned for his crime? Professional ethics forbade Huygens to take a life; still, he’d dreamed of killing Spaen. The unbearable torment of incarceration together on Deshima had made him desperate enough …

Loud barking outside signaled the guards’ return. Into the surgery they hauled a frisky black hound by a rope around its neck. Huygens said, “Tie the dog in the yard. Then wait here.”

The interpreter translated; the guards obeyed. Dr. Huygens went alone to the yard, carrying a club and a scalpel. The dog pranced and wagged its tail. “May God forgive me,” Huygens whispered. One hard blow on the skull, and the dog fell dead; several quick cuts to its neck, and Huygens held a long, white vein, still dripping warm blood, in his hands. He hurried back into the surgery and rinsed the vein in a water bucket.

“Sit on the table,” he told Nirin, “and roll up your sleeve so I can transfer some of your blood to your son.”

Looking apprehensive, Nirin did as the interpreter told him. Huygens took from his medical kit two canulas: tiny silver tubes, each with one end blunt and one cut at an angle and sharpened to a point. He prayed that the operation wouldn’t fail. Taking donor blood from the recipient’s near kin increased the chances of success, but while some patients revived and flourished, others died.

Huygens fingered the youth’s cold, flaccid arm and found a vein. When he pierced it with the sharp canula, the boy didn’t even flinch. Huygens turned to Nirin.