He got out of the car. Robin heard him say, “Hi,” before he slammed the door. She sat waiting for him, her mind buzzing. Either Strike had genuinely had a brainwave, or he was taking the mickey, and she slightly inclined to the latter, so utterly disconnected did the separate bits of information he had just listed seem.

Five minutes later, Strike returned to the passenger seat.

“Our client’s unhappy,” he reported, slamming the door again. “Tegan was supposed to be telling us that Kinvara crept back out that night to kill Chiswell, not confirming her alibi and blabbing about Chiswell flogging gallows.”

“Izzy admitted it?”

“Didn’t have much choice, did she? But she didn’t like it. Very insistent on telling me that exporting gallows was legal at the time. I put it to her that her father had defrauded Jimmy and Billy out of their money, and you were right. There were two sets of gallows built and ready to sell when Jack o’Kent died and nobody bothered to tell his sons. She liked admitting that even less.”

“D’you think she’s worried they’ll mount a claim on Chiswell’s estate?”

“I can’t see that it’d do Jimmy’s reputation much good in the circles he moves in, accepting money made from hanging people in the Third World,” said Strike, “but you never know.”

A car sped past on the road behind them and Strike craned around hopefully.

“Thought that might be Barclay…” He checked his watch. “Maybe he’s missed the turning.”

“Cormoran,” said Robin, who was far less interested in either Izzy’s mood or Barclay’s whereabouts than in the theory Strike was withholding from her, “have you seriously got an idea that explains everything you just told me?”

“Yeah,” said Strike, scratching his chin, “I have. Trouble is, it brings us closer to who, but I’m still damned if I can see why they did it, unless it was done out of blind hatred—but this doesn’t feel like a red-blooded crime of passion, does it? This wasn’t a hammer round the head. This was a well-planned execution.”

“What happened to ‘means before motive’?”

“I’ve been concentrating on means. That’s how I got here.”

“You won’t even tell me ‘he’ or ‘she’?”

“No good mentor would deprive you of the satisfaction of working it out for yourself. Any biscuits left?”

“No.”

“Lucky I’ve still got this, then,” Strike said, producing a Twix from his pocket, unwrapping it and handing her half, which she took with a bad grace that amused him.

Neither spoke until they had finished eating. Then Strike said, far more soberly than hitherto:

“Tonight’s important. If there’s nothing buried in a pink blanket at the bottom of the dell, the whole Billy business is finished: he imagined the strangling, we’ve set his mind at rest and I get to try and prove my theory about Chiswell’s death, unencumbered by distractions, without worrying where a dead kid fits in and who killed her.”

“Or him,” Robin reminded Strike. “You said Billy wasn’t sure which it was.”

As she said it, her unruly imagination showed her a small skeleton wrapped in the rotten remains of a blanket. Would it be possible to tell whether the body had been male or female from what was left? Would there be a hair grip or a shoelace, buttons, a hank of long hair?

Let there be nothing, she thought. God, let there be nothing there.

But aloud, she asked:

“And if there is—something—someone—buried in the dell?”

“Then my theory’s wrong, because I can’t see how a child strangling in Oxfordshire fits with anything I’ve just mentioned.”

“It doesn’t have to,” said Robin reasonably. “You could be right about who killed Chiswell, and this could be an entirely separate—”

“No,” Strike said, shaking his head. “It’s too much of a coincidence. If there’s something buried in the dell, it connects to everything else. One brother witnessing a murder as a child, the other blackmailing a murdered man twenty years later, the kid being buried on Chiswell’s land… if there’s a child buried in the dell, it fits in somewhere. But I’ll lay odds there’s nothing there. If I seriously thought there was a body in the dell, I’d’ve tried to persuade the police to do the job. Tonight’s for Billy. I promised him.”

They sat watching the track fade gradually from sight in the darkness, Strike occasionally checking his mobile.

“Where’s bloody Barclay got—? Ah!”

Headlights had just swung onto the track behind them. Barclay advanced an old Golf up the track and braked, turning off his lights. In her wing mirror, Robin watched his silhouette leave the car, turning into the flesh and blood Barclay as he reached Strike’s window, carrying a kit bag just like the detective’s.

“Evenin’,” he said laconically. “Nice night for a grave robbin’.”

“You’re late,” said Strike.

“Aye, I know. Just got a call from Flick. Thought you’d want tae hear what she’s got tae say.”

“Get in the back,” Strike suggested. “You can tell us while we’re waiting. We’ll give it ten minutes, make sure it’s properly dark.”

Barclay clambered into the back of the Land Rover and closed the doors. Strike and Robin twisted around in their seats to talk to him.

“So, she calls me, greetin’—”

“English translation, please.”

“Cryin’, then—not to mention shittin’ herself. The police came calling today.”

“’Bout bloody time,” said Strike. “And?”

“They searched the bathroom and found Chiswell’s note. She’s been interviewed.”

“What was her explanation for having it?”

“Didnae confide in me. All she wanted was to know where Jimmy is. She’s in a right fuckin’ state. It was all ‘just tell Jimmy they’ve got it, he’ll know whut I mean.’”

“Where is Jimmy, d’you know?”

“Havenae a scooby. Saw him yesterday and he didnae mention any plans, but he told me he’d pissed off Flick by askin’ if she had Bobbi Cunliffe’s number. He took a liking to young Bobbi,” said Barclay, grinning at Robin. “Flick told him she didnae know and wanted to know why he was so interested. Jimmy said he was jus’ tryin’ to get Bobbi along to a Real Socialist meetin’, but, y’know, Flick’s not that fuckin’ dumb.”

“D’you think she realizes it was me who tipped off the police?” asked Robin.

“Not yet,” said Barclay. “She’s panickin’.”

“All right,” said Strike, squinting up at the little of the sky they could see through the foliage overhead, “I think we should get started. Grab that bag beside you, Barclay, I’ve got tools and gloves in there.”

“How’re ye gonnae dig wi’ your leg like that?” asked Barclay skeptically.

“You can’t do it on your own,” said Strike, “we’ll still be here tomorrow night.”

“I’m digging, too,” said Robin firmly. She felt braver after Strike’s assurances that they were highly unlikely to find anything in the dell. “Pass me those wellies, Sam.”

Strike was already extracting torch and walking stick from his kit bag.

“I’ll carry it,” offered Barclay, and there was a sound of heavy metal tools shifting as he hoisted Strike’s bag onto his shoulder along with his own.

The three of them set off along the track, Robin and Barclay matching their pace to Strike’s, who progressed carefully, focusing the beam of his torch on the ground and making regular use of the stick, both to lean on and push obstacles out of his way. Their footsteps were deadened by the soft ground, but the quiet night amplified the chink and clatter of the tools carried by Barclay, the rustling of tiny, unseen creatures fleeing the giants who had invaded their wilderness and, from the direction of Chiswell House, the barking of a dog. Robin remembered the Norfolk terrier, and hoped he wasn’t loose.

When they reached the clearing, Robin saw that night had turned the derelict cottage

into a witch’s lair. It was easy to imagine figures lurking behind the cracked windows and, telling herself firmly that the situation was quite creepy enough without imagining fresh horrors, she turned away from it. With a soft “ooft,” Barclay let the kit bags fall onto the ground at the lip of the dell and unzipped both. By the light of the torch, Robin saw a wide array of tools: a pick, a mattock, two pinchbars, a fork, a small ax and three spades, one of them with a pointed head. There were also several pairs of thick gardening gloves.

“Aye, that should do us,” said Barclay, squinting into the dark basin below them. “We’ll want to clear that before we’ve got any chance o’ breakin’ the ground.”

“Right,” said Robin, reaching for a pair of gloves.

“Ye sure about this, big man?” Barclay asked Strike, who had done the same.

“I can pull up nettles, for Christ’s sake,” said Strike irritably.

“Bring the ax, Robin,” said Barclay, grabbing the mattock and a pinchbar. “Some o’ those bushes’ll need hacked down.”

The three of them slid and stumbled down the steep side of the dell and set to work. For nearly an hour they hacked at sinewy branches and tugged up nettles, occasionally swapping tools or returning to the upper ground to fetch different ones.

In spite of the gathering cool of the night, Robin was soon sweating, peeling off layers as she worked. Strike, on the other hand, was devoting a considerable amount of energy to pretending that the constant bending and twisting on slippery, uneven ground wasn’t hurting the end of his stump. The darkness concealed his winces, and he was careful to rearrange his features whenever Barclay or Robin turned on the torch to check on their progress.

Physical activity was helping dispel Robin’s fear of what could be hidden beneath their feet. Perhaps, she thought, this was what it was like in the army: hard manual work and the camaraderie of your colleagues helping you focus on something other than the grisly reality of what might lie ahead. The two ex-soldiers had bent to their task methodically and without complaint except for occasional curses as stubborn roots and branches tore at fabric and flesh.

“Time tae dig,” said Barclay at last, when the bottom of the basin was as clear as they could reasonably make it. “Ye’ll need to get out of it, Strike.”

“I’ll start, Robin can take over,” said Strike. “Go on,” he said to her, “take a break, hold the torch steady for us and pass me down the fork.”

Growing up with three brothers had taught Robin valuable lessons about the male ego, and about picking her fights. Convinced that Strike’s order was dictated more by pride than by sense, she nevertheless complied, clambering up the steep side of the dell, there to sit and hold the beam of the torch steady while they worked, occasionally passing down different tools to help them remove rocks and tackle particularly hard stretches of ground.

It was a slow job. Barclay dug three times as fast as Strike, who Robin could see was immediately struggling, especially with pressing the pointed head spade down into the earth with a foot, his prosthesis being unreliable if asked to support his entire weight on the uneven ground, and excruciating when pressed down against resistant metal. Minute by minute she held off intervening, until a muttered “fuck” escaped Strike, and he bent over, grimacing in pain.

“Shall I take over?” she suggested.

“Think you’re going to have to,” he muttered ungraciously.

He dragged himself back out of the dell, trying not to put any more weight on his stump, taking the torch from a descending Robin and holding it steady for the other two as they worked, the end of his stump throbbing and, he suspected, rubbed raw.

Barclay had created a short channel a couple of feet deep before he took his first break, clambering out of the hole to fetch a bottle of water from his kit bag. While he drank and Robin took a rest, leaning on the handle of her spade, the sound of barking reached them again. Barclay squinted towards the unseen Chiswell House.

“What kind of dogs has she got in there?” he asked.

“Old Lab and a yappy bastard of a terrier,” said Strike.

“Don’t like our chances if she lets them oot,” said Barclay, wiping his mouth on his arm. “Terrier’ll get straight through those bushes. They’ve got fuckin’ good hearin’, terriers.”

“Better hope she doesn’t let them out, then,” said Strike, but he added, “Give it five, Robin,” and turned off the torch.

Robin, too, climbed out of the basin and accepted a fresh bottle of water from Barclay. Now that she was no longer digging, the chill made her exposed flesh creep. The fluttering and scurrying of small creatures in the grass and trees seemed extraordinarily loud in the darkness. Still the dog barked, and, distantly, Robin thought she heard a woman shout.

“Did you hear that?”

“Aye. Sounded like she was telling it to shut up,” said Barclay.

They waited. At last, the terrier stopped barking.

“Give it a few more minutes,” said Strike. “Let it fall asleep.”

They waited, the whispering of every leaf magnified in the darkness, until Robin and Barclay lowered themselves back into the dell and began to dig again.

Robin’s muscles were now begging for mercy, her palms beginning to blister beneath the gloves. The deeper they dug, the harder the job became, the soil compacted and full of rocks. Barclay’s end of the trench was considerably deeper than Robin’s.

“Let me do a bit,” Strike suggested.

“No,” she snapped, too tired to be anything but blunt. “You’ll bugger your leg completely.”

“She’s nae wrong, pal,” panted Barclay. “Gie’s another drink of water, I’m gaspin’.”

An hour later, Barclay was standing waist deep in soil and Robin’s palms were bleeding beneath the overlarge gloves, which were rubbing away layers of skin as she used the blunt end of the mattock to try and prize a heavy rock out of the ground.

“Come—on—you—bloody—thing—”

“Want a hand?” offered Strike, readying himself to descend.

“Stay there,” she told him angrily. “I’m not going to be able to help carry you back to the car, not after this—”

A final, involuntary yelp escaped her as she succeeded in overturning the small boulder. A couple of tiny, wriggling insects attached to the underside slid away from the torchlight. Strike directed the beam back on Barclay.

“Cormoran,” said Robin sharply.

“What?”

“I need light.”

Something in her voice made Barclay stop digging. Rather than direct the beam back at her, and disregarding her warning of a moment ago, Strike slid back down into the pit, landing on the loose earth. The torchlight swung around, blinding Robin for a second.

“What’ve you seen?”

“Shine it here,” she said. “On the rock.”

Barclay clambered towards them, his jeans covered from hem to pockets in soil.

Strike did as Robin asked. The three of them peered down at the encrusted surface of the rock. There, stuck to the mud, was a strand of what was plainly not vegetable matter, but wool fibers, faintly but distinctly pink.

They turned in unison to examine the indentation left in the ground where the rock had sat, Strike directing the torchlight into the hole.

“Oh, shit,” gasped Robin, and without thinking she clapped two muddy garden gloves to her face. A couple of inches of filthy material had been revealed, and in the strong beam of the torch, it, too, was pink.

“Give me that,” said Strike, tugging the mattock out of her hand.

“No—!”

But he almost pushed her aside. By the deflected torchlight she could see his expression, forbidding, furious, as though the pink blanket had grievously wronged him, as though he had suffered a personal affront.

“Barclay, you take this.”

He thrust the mattock at his subcontractor.

“Break this up, as much as you can. Try not to puncture the blanket. Robin, go to th

e other end. Use the fork. And mind my hands,” Strike told Barclay. Sticking the torch in his mouth so that he could see by its light, he fell to his knees in the dirt and began to move earth aside with his fingers.

“Listen,” whispered Robin, freezing.

The sound of the terrier’s frenzied barking reached them once again through the night air.

“I yelled, didn’t I, when I overturned the rock?” whispered Robin. “I think I woke it up again.”

“Never mind that now,” said Strike, his fingers prizing dirt away from the blanket. “Dig.”

“But what if—?”

“We’ll deal with that if it happens. Dig.”

Robin plied the fork. After a couple of minutes, Barclay swapped the mattock for a shovel. Slowly, the length of the pink blanket, its contents still buried too deep to remove, was revealed.

“That’s no adult,” said Barclay, surveying the stretch of filthy blanket.

And still, the terrier continued to yap, distantly, from the direction of Chiswell House.

“We should call the polis, Strike,” said Barclay, pausing to wipe sweat and mud out of his eyes. “Are we no disturbing a crime scene, here?”

Strike didn’t answer. Feeling slightly sick, Robin watched his fingers feeling the shape of the thing that was hidden beneath the filthy blanket.

“Go up to my kit bag,” he told her. “There’s a knife in there. Stanley knife. Quickly.”

The terrier was still yapping distractedly. Robin thought it sounded louder. She clambered up the steep side of the dell, groped around in the dark depths of the bag, found the knife and slid back down to Strike.

“Cormoran, I think Sam’s right,” she whispered. “We should leave this to the—”

“Give me the knife,” he said, holding out his hand. “Come on, quick, I can feel it. This is the skull. Quickly!”

Against her better instincts, she handed over the blade. There was a sound of puncturing fabric and then a ripping.

“What are you doing?” she gasped, watching Strike tugging at something in the ground.

“Jesus fuck, Strike,” said Barclay angrily, “are ye tryin’ to rip off its—?”