Although the lower part of Wen Lo’s face smiled, his eyes didn’t mirror the same pleasant expression.

“Please show me your progress, Dr. Wu.”

“I’d be glad to, sir.”

Wu led Wen Lo and his personal bodyguard through two sets of airtight chambers and along a short corridor that ended in a thick glass door. Responding to a gesture from Wu, a guard pressed an electrical switch that unlocked the door. Wu, Wen Lo, and the bodyguard stepped into a cellblock. Steel doors, solid except for small rectangular openings, enclosed a dozen cells.

As they walked between the cells, Dr. Wu said, “The men and women are segregated, four to a cell. We maintain full occupancy at all times.”

A few inmates pushed their faces close to the barred openings and called out to Wu and his guests to help them. Wen Lo, his face devoid of pity, turned to Wu.

“What is the source of these lab rats?” he asked.

Dr. Wu was rewarded handsomely enough for his work to afford a large apartment in a new high-rise overlooking the Yangtze and to keep his wife and his mistress clothed in the latest fashions, but he had convinced himself that his research was for the good of mankind. Although his work required that he suppress his humanity under a thin veneer of medical noninvolvement, the coldness of Wen Lo’s question stunned him. He was, after all, still a physician.

“As medical professionals, we prefer to call them subjects,” he said.

“Very well, Dr. Wu, I’m sure these subjects appreciate your professionalism. But you haven’t answered my question.”

“My apologies, sir,” Wu said. “This lab is surrounded by teeming slums, and it’s easy to lure the subjects in with promises of food and money. We choose only those in relatively good physical shape. People in the slums rarely report the missing, and the police never follow up.”

Wen Lo said, “Show me the next phase. I have seen prisons before.”

Wu escorted the two men out of the cellblock to a black-walled room. One wall was half glass, like the viewing area for a maternity ward. Visible through the glass were a number of full-sized beds, each occupied and enclosed in a transparent cylinder.

The occupants of the beds were quiet for the most part, but occasionally someone stirred restlessly under a tightly tucked sheet. Figures in white body-encasing protective suits moved like ghosts among the beds, checking electronic monitors and IV tubes.

“This is one of several sick rooms,” Wu said. “The subjects in each have been injected with the new pathogen and are proceeding through the stages of the virus. Although the virus is waterborne, it can be spread through contact as well. You can see by the way the technicians are dressed, and the separately vented enclosures for each subject, that we take every precaution to keep the disease contained to the rooms.”