"I haven't excavated all the graves yet," Montoya said, "and it's still raining. They have to send someone out immediately."

"Graves?" Mary said, looking at him uncomprehendingly. "What is she talking about?"

"She's been excavating a mediaeval churchyard looking for Kivrin's body," he said bitterly, "looking for the corder you implanted in Kivrin's wrist."

Mary wasn't listening. "I want the contacts charts," she said to the house officer. She turned back to Dunworthy. "Badri was out at the dig, wasn't he?"

"Yes."

"When?"

"The eighteenth and nineteenth," he said.

"In the churchyard?"

"Yes. He and Montoya were opening a knight's tomb."

"A tomb," Mary said, as if it were the answer to a question. She bent over Montoya. "Did you work on the knight's tomb this week?" she asked.

Montoya tried to nod, stopped. "I get so dizzy when I move my head," she said apologetically. "I had to move the skeleton. Water'd gotten into the tomb."

"What day did you work on the tomb?"

Montoya frowned. "I can't remember. The day before the bells, I think."

"The thirty-first," Dunworthy said. He leaned over her. "Have you worked on it since?"

She tried to shake her head again.

"The contacts charts are up," the house officer said.

Mary walked rapidly over to his desk and took the keyboard over from him. She tapped several keys, stared at the screen, tapped more keys.

"What is it?" Dunworthy said.

"What are the conditions at the churchyard?" Mary said.

"Conditions?" he said blankly. "It's muddy. She's covered the churchyard with a tarp, but a good deal of rain was still getting in."

"Warm?"

"Yes. She said it was muggy. She had several electric fires hooked up. What is it?"

She drew her finger down the screen, looking for something. "Viruses are exceptionally sturdy organisms," she said. "They can lie dormant for long periods of time and be revived. Living viruses have been taken from Egyptian mummies." Her finger stopped at a date. "I thought so. Badri was at the dig four days before he came down with the virus."

She turned to the house officer. "I want a team out at the dig immediately," she told him. "Get NHS clearance. Tell them we may have found the source of the virus." She typed in a new screen, drew her finger down the names, typed in something else, and leaned back, looking at the screen. "We had four secondaries with no positive connection to Badri. Two of them were at the dig four days before they came down with the virus. The other one was there three days before."

"The virus is at the dig?" Dunworthy said.

"Yes." She smiled ruefully at him. "I'm afraid Gilchrist was right after all. The virus did come from the past. Out of the knight's tomb."

"Kivrin was at the dig," he said.

Now it was Mary who looked uncomprehending. "When?"

"The Sunday afternoon before the drop. The nineteenth."

"Are you certain?"

"She told me before she left. She wanted her hands to look authentic."

"Oh, my God," she said. "If she was exposed four days before the drop, she hadn't had her T-cell enhancement. The virus might have had a chance to replicate and invade her system. She might have come down with it."

Dunworthy grabbed her arm. "But that can't have happened. The net wouldn't have let her through if there was a chance she'd infect the contemps."

"There wasn't any one for her to infect," Mary said, "not if the virus came out of the knight's tomb. He died of it in 1118. The contemps had already had it. They'd be immune." She walked rapidly over to Montoya. "When Kivrin was out at the dig, did she work on the tomb?"

"I don't know," Montoya said. "I wasn't there. I had a meeting with Gilchrist."

"Who would know? Who else was there that day?"

"No one. Everyone had gone home for vac."

"How did she know what she was supposed to do?"

"The volunteers left notes to each other when they left."

"Who was there that morning?" Mary asked.

"Badri," Dunworthy said and took off for isolation.

He walked straight into Badri's room. The nurse, caught off-guard with her swollen feet up on the displays, said, "You can't go in without SPG's," and started after him, but he was already inside.

Badri was lying propped against a pillow. He looked very pale, as if his illness had bleached all the color from his skin, and weak, but he looked up when Dunworthy burst in and started to speak.

"Did Kivrin work on the knight's tomb?" Dunworthy demanded.

"Kivrin?" His voice was almost too weak to be heard.

The nurse banged in the door. "Mr. Dunworthy, you are not allowed in here — "

"On Sunday," Dunworthy said. "You were to have left her a message telling her what to do. Did you tell her to work on the tomb?"

"Mr. Dunworthy, you're exposing yourself to the virus — " the nurse said.

Mary came in, pulling on a pair of imperm gloves. "You're not supposed to be in here without SPG's, James," she said.

"I told him, Dr. Ahrens," the nurse said, but he barged past me and — "

"Did you leave Kivrin a message at the dig that she was to work on the tomb?" Dunworthy insisted.

Badri nodded his head weakly.

"She was exposed to the virus," Dunworthy said to Mary. "On Sunday. Four days before she left."

"Oh, no," Mary breathed.

"What is it? What's happened?" Badri said, trying to push himself up in the bed. "Where's Kivrin?" He looked from Dunworthy to Mary. "You pulled her out, didn't you? As soon as you realized what had happened? Didn't you pull her out?"

"What had happened — ?" Mary said.

"You have to have pulled her out," Badri said. "She's not in 1320. She's in 1348."

CHAPTER TWENTY-FIVE

"That's impossible," Dunworthy said.

"1348?" Mary said bewilderedly. "But that can't be. That's the year of the Black Death."

She can't be in 1348, Dunworthy thought. Andrews said the possible maximal slippage was only five years. Badri said Puhalski's coordinates were correct.

"1348?" Mary said again. He saw her glance at the screens on the wall behind Badri, as if hoping he was still delirious. "Are you certain?"

Badri nodded. "I knew something was wrong as soon as I saw the slippage — ," he said, and sounded as bewildered as Mary.

"There couldn't have been enough slippage for her to be in 1348," Dunworthy cut in. "I had Andrews run parameter checks. He said the maximal slippage was only five years."

Badri shook his head. "It wasn't the slippage. That was only four hours. It was too small. Minimal slippage on a drip that far in the past should have been at least forty-eight hours."

The slippage had not been too great. It had been too small. I didn't ask Andrews what the minimal slippage was, only the maximal.

"I don't know what happened," Badri said. "I had such a headache. The whole time I was setting the net, I had a headache."

"That was the virus," Mary said. She looked stunned. "Headache and disorientation are the first symptoms." She sank down in the chair beside the bed. "1348."

1348. He could not seem to take this in. He had been worried about Kivrin catching the Indian flu, he had been worried about there being too much slippage, and all the time she was in 1348. The plague had hit Oxford in 1348. At Christmastime.

"As soon as I saw how small the slippage was, I knew there was something wrong," Badri said, so I called up the coordinates- -"

"You said you checked Puhalski's coordinates," Dunworthy said accusingly.

"He was only a first-year apprentice. He'd never even done a remote. And Gilchrist didn't have the least idea what he was doing. I tried to tell you. Wasn't she at the rendezvous?" He looked at Dunworthy. "Why didn't you pull her out?"

"We didn't know," Mary said, still sitting there stunned. "You weren't able to tell us anything. You were delirious."