Adelia crossed herself and walked away, putting her penny onto the table of the clerk at the door. “Are you cured, mistress?” he asked her. “I must record any miracles.”

“You may put down that I feel better,” she said.

“Justified” would have been a more accurate word; she knew where she was now. Little Saint Peter had not been crucified; he had died even more obscenely. Like the others.

And how to declare that to a coroner’s inquest? she thought, sourly. I, Dr. Trotula, have physical proof that this boy did not die on a cross but at the hands of a butcher who still walks among you.

Play that to a jury knowing nothing of anatomical sciences and caring less, demonstrated to them by a foreign woman.

It wasn’t until she was outside in the air that she realized Ulf had not come in with her. She found him sitting on the ground by the gates with his arms round his knees.

It occurred to Adelia that she had been unthinking. “Were you acquainted with Little Saint Peter?”

Labored sarcasm was addressed to the Safeguard. “Never went to bloody school with un wintertime, did I? ’Course I never.”

“I see. I am sorry.” She had been thoughtless; the skeleton back there was once a schoolfellow and a friend to this one, who, presumably, must grieve for him. She said politely, “However, not many of us can say we attended lessons with a saint.”

The boy shrugged.

Adelia was unacquainted with children; mostly she dealt with dead ones. She saw no reason to address them other than as cognitive human beings, and when they did not respond, like this one, she was at a loss.

“We will go back to Saint Radegund’s tree,” she said. She wanted to talk to the nuns there.

They retraced their steps. A thought struck Adelia. “By any chance did you see your schoolfellow on the day he disappeared?”

The boy rolled his eyes at the dog in exasperation. “Easter that was. Easter me and Gran was still in the fens.”

“Oh.” She walked on. It had been worth a try.

Behind her, the boy addressed the dog: “Will did, though. Will was with him, wasn’t he?”

Adelia turned round. “Will?”

Ulf tutted; the dog was being obtuse. “Him and Will was picking pussy willow both.”

There’d been no mention of a Will in the account of Little Saint Peter’s last day that Prior Geoffrey had given to Simon and that Simon had passed on to her. “Who is Will?”

When the child was about to speak to the dog, Adelia put her hand on the boy’s head and screwed it round to face her. “I would prefer it if you talked directly to me.”

Ulf retwisted his neck so that he could look back at the Safeguard. “We don’t like her,” he told it.

“I don’t like you, either,” Adelia pointed out, “but the matter at issue is who killed your schoolmate, how, and why. I am skilled in the investigation of such things, and in this case I have need of your local knowledge-to which, since you and your grandmother are in my employment, I am entitled. Our liking for each other, or lack of it, is irrelevant.”

“Jews bloody did it.”

“Are you sure?”

For the first time, Ulf looked straight at her. Had the tax collector been with them at that moment, he would have seen that, like Adelia’s when she was working, the boy’s eyes aged the face they were set in. Adelia saw an almost appalling shrewdness.

“You come along o’ me,” Ulf said.

Adelia wiped her hand down her skirt-the child’s hair where it stuck out from his cap had been greasy and quite possibly inhabited-and followed him. He stopped.

They were looking across the river at a large and imposing mansion with a lawn that led down to a small pier. Closed shutters on every window and weeds growing from the gutters showed it to be abandoned.

“Chief Jew’s place,” Ulf said.

“Chaim’s house? Where Peter was assumed to have been crucified?”

The boy nodded. “Only he weren’t. Not then.”

“My information is that a woman saw the body hanging in one of the rooms.”

“Martha,” the boy said, his tone putting the name into the same category as rheumatism, unadmired but to be put up with. “That’ll say anything to get her bloody noticed.” As if he’d gone too far in condemning a fellow Cambriensan, he added, “I ain’t saying her never, I’m saying her never bloody see it when her says she did. Like old Peaty. Look here.”

They were off again, past Saint Radegund’s willow and its stall of branches, to the bridge.

Here was where a man delivering peat to the castle had seen two Jews casting a bundle, presumed to be the body of Little Peter, into the Cam. She said, “The peat seller was also mistaken?”

The boy nodded. “Old Peaty, he’m half blind and a wormy old liar. He didn’t see nothing. Acause…”

Now they were returning the way they’d come, back to the spot opposite Chaim’s house.

“Acause,” said Ulf, pointing to the empty pier protruding into the water, “Acause that’s where they found the body. Caught under them bloody stanchions like. So nobody threw nothing over the bridge acause…?”

He looked at her expectantly; this was a test.

“Because,” Adelia said, “bodies do not float upstream.”

The worldly wise eyes were suddenly amused, like those of a teacher whose student had unexpectedly come up to scratch. She’d passed.

But if the testimony of the peat seller was so obviously false, thus casting doubt on that of the woman who claimed that only a little while before, she had seen the crucified body of the child in Chaim’s house, why had the finger of guilt pointed straight at the Jews?

“Acause they bloody did it,” the boy said, “only not then.” He gestured with a grubby hand for her to sit down on the grass, then sat beside her. He began talking fast, allowing her entrance into a world of juveniles who formed theory based on data differently observed and at odds with the conclusions of adults.

Adelia had difficulty following not only the accent but the patois; she leaped onto phrases she could recognize as if jumping from tussock to tussock across a morass.

Will, she gathered, was a boy of about Ulf’s age, and he had been on the same errand as Peter, to gather pussy willow for Palm Sunday decoration. Will lived in Cambridge proper, but he and the boy from Trumpington had encountered each other at Saint Radegund’s tree, where both had been attracted by the sight of the wedding celebrations on Chaim’s lawn across the river. Will had thereupon accompanied Peter over the bridge and through the town in order to see what was to be seen in the stables at the back of Chaim’s house.

Afterward, Will had left his companion to take the needed willow branches back home to his mother.

There was a pause in the narration, but Adelia knew there was more to come-Ulf was a born storyteller. The sun was warm, and it was not unpleasant to sit in the dappling shade of the willows, though Safeguard’s coat had acquired something noisome on the walk that became more pungent as it dried. Ulf, with his prehensile little feet in the river, complained of hunger. “Give us a penny and I’ll go to the pie shop for us.”

“Later.” Adelia prodded him on. “Let me recapitulate. Will went home and Peter disappeared into Chaim’s house, never to be seen again.”

The child gave a mocking sniff. “Never to be seen by any bugger ’cept Will.”

“Will saw him again?”

It had been later that day, getting dark. Will had returned to the Cam to bring a supper pail to his father, who was working into the night caulking one of the barges ready for the morning.

And Will on the Cambridge side had seen Peter across the river, standing on the left bank-“Here he was, right here. Where we’re bloody sitting.” Will had called out to Peter that he should be getting home.

“So he ought’ve,” Ulf added, virtuously, “you get caught in them Trumpington marshes of a night, will o’the wisps lead you down to the Pit.”