Dunworthy had a sudden image of Badri leaning over Kivrin, adjusting her sleeve, moving her arm.

"Anyone at all who may have been exposed," Mary said.

"Including all of us," the medic said.

"Yes," Mary said.

"And Kivrin," Dunworthy said.

For a moment she looked like she had no idea at all who Kivrin was.

"Ms. Engle has had full-spectrum antivirals and T-cell enhancement," Gilchrist said. "She would not be at risk, would she?"

Dr. Ahrens hesitated only a second. "No. She didn't have any contact with Badri before this morning, did she?"

"Mr. Dunworthy only offered me the use of his tech two days ago," Gilchrist said, practically snatching the papers and pencil the nurse was offering him out of her hands. "I, of course, assumed that Mr. Dunworthy had taken the same precautions with his techs which Mediaeval had. It has become apparent, however, that he didn't, and you may be sure I will inform Basingame of your negligence, Mr. Dunworthy."

"If Kivrin's first contact with Badri was this morning, she was fully protected," Mary said. "Mr. Gilchrist, if you'd be so good." She indicated the chair, and he came and sat down.

Mary took one of the sets of papers from the nurse and held up the sheet marked "Primaries." "Any person Badri had contact with is a primary contact. Any person you have had contact with is a secondary. On this sheet I would like you to list all contacts you have had with Badri Chaudhuri over the last three days, and any contacts of his that you know of. On this sheet," she held up the sheet marked "Secondaries", "list all your contacts with the time you had them. Begin with the present and work backward."

She popped a temp into Gilchrist's mouth, peeled a portable monitor off its paper strip, and stuck it on his wrist. The nurse passed the papers out to Latimer and the medic. Dunworthy sat down and began filling out his own.

The Infirmary form asked for his name, National Health Service number, and a complete medical history, which the NHS number could no doubt call up in better detail than he could remember it. Illnesses. Surgeries. Inoculations. If Mary didn't have Badri's NHS number that meant he was still unconscious.

Dunworthy had no idea what date his last start-of-term antivirals had been. He put question marks next to them, turned to the Primaries sheet, and wrote his own name at the top of the column. Latimer, Gilchrist, the two medics. He didn't know their names, and the female medic was asleep again. She held her papers bunched in one hand, her arms folded across her chest. Dunworthy wondered if he needed to list the doctors and nurses who had worked on Badri when he came in. He wrote "casualties department staff" and then put a question mark after it. Montoya.

And Kivrin, who, according to Mary, was fully protected. "Something wrong," Badri had said. Had he meant this infection? Had he realized he was getting ill while he was trying to get the fix and come running to the pub to tell them he had exposed Kivrin?

The pub. There hadn't been anyone in the pub except the barman. And Finch, but he'd gone before Badri got there. Dunworthy lifted up the sheet and wrote Finch's name under "Secondaries," and then turned back to the first sheet and wrote "barman, Lamb and Cross." The pub had been empty, but the streets hadn't been. He could see Badri in his mind's eye, pushing his way through the Christmas crowd, barging into the woman with the flowered umbrella and elbowing his way past the old man and the little boy with the white terrier. "Anyone he's had any contact with," Mary had said.

He looked across at Mary, who was holding Gilchrist's wrist and making careful entries in a chart. Was she going to try to get bloods and temps from everyone on these lists? It was impossible. Badri had touched or brushed past or breathed on dozens of people in his headlong flight back to Brasenose, none of whom Dunworthy or Badri, would recognize again. Doubtless he had come in contact with as many or more on his way to the pub, and each of them had come in contact with how many others in the busy shops?

He wrote down "Large number of shoppers and pedestrians, High Street(?)" drew a line, and tried to remember the other occasions on which he'd seen Badri. He hadn't asked him to run the net until two days ago, when he'd found out from Kivrin that Gilchrist was intending to use a first-year apprentice.

Badri had just gotten back from London when Dunworthy telephoned. Kivrin had been in hospital that day for her final examination, which was good. She couldn't have had any contact with him then, and he'd been in London before that.

Tuesday Badri had come to see Dunworthy to tell him he'd checked the first-year student's coordinates and done a full systems check. Dunworthy hadn't been there, so he'd left a note. Kivrin had come to Balliol Tuesday, as well, to show him her costume, but that had been in the morning. Badri had said in his note that he'd spent all morning at the net. And Kivrin had said she was going to see Latimer at the Bodleian in the afternoon. But she might have gone back to the net after that, or have been there before she came to show him her costume.

The door opened and the nurse ushered Montoya in. Her terrorist jacket and jeans were wet. It must still be raining. "What's going on?" she said to Mary, who was labelling a vial of Gilchrist's blood.

"It seems," Gilchrist said, pressing a wad of cotton wool to the inside of his arm and standing up, "that Mr. Dunworthy failed to have his tech properly checked for inoculations before he ran the net, and now he is in hospital with a temperature of 39.5. He apparently has some sort of exotic fever."

"Fever?" Montoya said, looking bewildered. "Isn't 39.5 low?"

"103 degrees in Fahrenheit," Mary said, sliding the vial into its carrier. "Badri's infection is possibly contagious. I need to run some tests and you'll need to write down all of your contacts and Badri's."

"Okay," Montoya said. She sat down in the chair Gilchrist had vacated and shrugged off her jacket. Mary swabbed the inside of her arm and clipped a new vial and disposable punch together. "Let's get it over with. I've got to get back to my dig."

"You can't go back," Gilchrist said. "Haven't you heard? We're under quarantine, thanks to Mr. Dunworthy's carelessness."

"Quarantine?" she said and jerked so the punch missed her arm completely. The idea of a disease she might contract had not affected her at all, but the mention of a quarantine did. "I have to get back," she said, appealing to Mary. "You mean I have to stay here?"

"Until we have the blood test results," Mary said, trying to find a vein for the punch.

"How long will that be?" Montoya said, trying to look at her digital with the arm Mary was working on. "The guy who brought me in didn't even let me cover up the site or turn off the heaters, and it's raining like crazy out there. I've got a churchyard that's going to be full of water if I don't get out there."

"As long as it takes to get blood samples from all of you and run an antibodies count on them," Mary said, and Montoya must have gotten the message because she straightened out her arm and held it still. Mary filled a vial with her blood, gave her her temp, and slid a tach bracelet on. Dunworthy watched her, wondering if she had been telling the truth. She hadn't said Montoya could leave after they had the test results, only that she had to stay here until they were in. And what then? Would they be taken to an isolation ward together or separately? Or given some sort of medication? Or given more tests?

Mary took Montoya's tach bracelet off and handed her the last set of papers. "Mr. Latimer? You're next."

Latimer stood up, holding his papers. He looked at them confusedly, then set them down on the chair he'd been sitting on, and started over to Mary. Halfway there, he turned and went back for Mary's shopping bag. "You left this at Brasenose," he said, holding it out to Mary.