Sarah insisted on wiggling around the table to embrace Robin, something the latter was sure she would not have done had she not been with men.

“Darling, what’s happened to you? You’re all sticky!”

She was just a little posher here, in Mayfair, than anywhere else Robin had met her, and several degrees warmer to Robin.

“Nothing,” muttered Robin. “Spilled orange juice, that’s all.”

“Cormoran!” said Sarah blithely, swooping in for a kiss on his cheek. Strike, Robin was pleased to note, sat impassive and did not respond. “Bit of R and R?” said Sarah, embracing them both in her knowing smile.

“Work,” said Strike bluntly.

Receiving no encouragement to stay, Sarah moved along the bar, taking her colleagues with her.

“I forgot Christie’s is round the corner,” muttered Robin.

Strike checked his watch. He didn’t want to have to wear his suit to Lorelei’s, and indeed, it was now stained with orange juice from having taken Robin’s seat.

“We need to talk about how we’re going to do this job, because it starts tomorrow.”

“OK,” said Robin with some trepidation, because it had been a long time since she had worked a weekend. Matthew had got used to her coming home.

“It’s all right,” said Strike, apparently reading her mind, “I won’t need you till Monday.

“The job’s going to take three people at a minimum. I reckon we’ve already got enough on Webster to keep the client happy, so we’ll put Andy full time on Dodgy Doc, let the two waiting-list clients know we’re not going to be able to do them this month and Barclay can come in with us on the Chiswell case.

“On Monday, you’re going into the House of Commons.”

“I’m what?” said Robin, startled.

“You’re going to go in as Chiswell’s goddaughter, who’s interested in a career in Parliament, and get started on Geraint, who runs Della’s constituency office at the other end of the corridor to Chiswell’s. Chat him up…”

He took a swig of beer, frowning at her over the top of the glass.

“What?” said Robin, unsure what was coming.

“How d’you feel,” said Strike, so quietly that she had to lean in to hear him, “about breaking the law?”

“Well, I tend to be opposed to it,” said Robin, unsure whether to be amused or worried. “That’s sort of why I wanted to do investigative work.”

“And if the law’s a bit of a gray area, and we can’t get the information any other way? Bearing in mind that Winn’s definitely breaking the law, trying to blackmail a Minister of the Crown out of his job?”

“Are you talking about bugging Winn’s office?”

“Right in one,” said Strike. Correctly reading her dubious expression, he went on. “Listen, by Chiswell’s account, Winn’s a slapdash loudmouth, which is why he’s stuck in the constituency office and kept well away from his wife’s work at the Department for Sport. Apparently he leaves his office door open most of the time, shouts about constituents’ confidential affairs and leaves private papers lying around in the communal kitchen. There’s a good chance you’ll be able to inveigle indiscretions out of him without needing the bug, but I don’t think we can count on it.”

Robin swilled the last of her orange juice in her glass, deliberating, then said:

“All right, I’ll do it.”

“Sure?” said Strike. “OK, well you won’t be able to take devices in, because you’ll have to go through a metal detector. I’ve said I’m going to get a handful to Chiswell tomorrow. He’ll pass them to you once you’re inside.

“You’ll need a cover name. Text it to me when you’ve thought of one so I can let Chiswell know. You could use ‘Venetia Hall’ again, actually. Chiswell’s the kind of bloke who’d have a goddaughter called Venetia.”

“Venetia” was Robin’s middle name, but Robin was too full of apprehension and excitement to care that Strike, from his smirk, continued to find it amusing.

“You’re going to have to work a disguise as well,” said Strike. “Nothing major, but Chiswell remembered what you look like from the Ripper coverage, so we’ve got to assume Winn might, too.”

“It’ll be too hot for a wig,” she said. “I might try colored contact lenses. I could go and buy some now. Maybe some plain-lensed glasses on top.” A smile she could not suppress surfaced again. “The House of Commons!” she repeated excitedly.

Robin’s excited grin faded as Sarah Shadlock’s white-blonde head intruded on the periphery of her vision, on the other side of the bar. Sarah had just repositioned herself to keep Robin and Strike in her sights.

“Let’s go,” Robin said to Strike.

As they walked back towards the Tube, Strike explained that Barclay would be tailing Jimmy Knight.

“I can’t do it,” said Strike regretfully. “I’ve blown my cover with him and his CORE mates.”

“So what will you be up to?”

“Plug gaps, follow up leads, cover nights if we need them,” said Strike.

“Poor Lorelei,” said Robin.

It had slipped out before she could stop herself. Increasingly heavy traffic was rolling past, and when Strike did not answer, Robin hoped that he hadn’t heard her.

“Did Chiswell mention his son who died in Iraq?” she asked, rather like a person hastily coughing to hide a laugh that has already escaped them.

“Yeah,” said Strike. “Freddie was clearly his favorite child, which doesn’t say much for his judgment.”

“What d’you mean?”

“Freddie Chiswell was a prize shit. I investigated a lot of Killed in Actions, and I never had so many people ask me whether the dead officer had been shot in the back by his own men.”

Robin looked shocked.

“De mortuis nil nisi bonum?” asked Strike.

Robin had learned quite a lot of Latin, working with Strike.

“Well,” she said quietly, for the first time finding some pity in her heart for Jasper Chiswell, “you can’t expect his father to speak ill of him.”

They parted at the top of the street, Robin to shop for colored contact lenses, Strike heading for the Tube.

He felt unusually cheerful after the conversation with Robin: as they contemplated this challenging job, the familiar contours of their friendship had suddenly resurfaced. He had liked her excitement at the prospect of entering the House of Commons; liked being the one who had offered the chance. He had even enjoyed the way she stress-tested his assumptions about Chiswell’s story.

On the point of entering the station, Strike turned suddenly aside, infuriating the irate businessman who had been walking six inches in his wake. Tutting furiously, the man barely avoided a collision and strode off huffily into the Underground while the indifferent Strike leaned up against the sun-soaked wall, enjoying the sensation of heat permeating his suit jacket as he phoned Detective Inspector Eric Wardle.

Strike had told Robin the truth. He didn’t believe that Chiswell had ever strangled a child, yet there had been something undeniably odd about his reaction to Billy’s story. Thanks to the minister’s revelation that the Knight family had lived in proximity to his family home, Strike now knew that Billy had been a “little kid” in Oxfordshire. The first logical step in assuaging his continued unease about that pink blanket was to find out whether any children in the area had disappeared a couple of decades ago, and never been found.