“You think?” said Strike thickly, through his first mouthful of noodles.

“Yes,” said Robin. “We’ve all got a tendency to generalize from our own past experiences. Look at Violet Cooper. She thought she knew who Creed really was, because she’d met a couple of men who behaved like him, in her theater days.”

“Men who wouldn’t let anyone in their basement flats because they were boiling down skulls?”

“You know what I mean, Strike,” said Robin, refusing to be amused. “Soft-spoken, apparently gentle, slightly feminine. Creed liked putting on her feather boa, and he pretended to like show tunes, so she thought he was a gay man. But if the only gay man she’d met had been Max, my flatmate…”

“He’s gay, is he?” said Strike, whose memories of Max were indistinct.

“Yes, and he isn’t remotely camp, and hates musicals. Come to that, if she’d met a couple of Matt’s straight mates down the rugby club, who couldn’t wait to shove oranges up their T-shirts and prance around, she might’ve drawn a different conclusion, mightn’t she?”

“S’pose so,” said Strike, chewing noodles and considering this point. “And in fairness, most people don’t know any serial killers.”

“Exactly. So even if somebody’s got some unusual habits, our direct experience tends to suggest they’re just eccentric. Vi had never met a man who fetishised women’s clothing or… sorry, I’m boring you,” Robin added, because Strike’s eyes seemed to have glazed over.

“No, you aren’t,” he muttered. “You’re actually making me think… I had an idea, you know. I thought I’d spotted some coinci-dences, and it got me wondering…”

He set down the pot of noodles, reached under the desk and pulled one of the boxes of police evidence toward him, on top of which lay the pages he’d last been re-examining. He now took these bits of paper out, spread them in front of himself again, and resumed his noodle-eating.

“Are you going to tell me about the coincidences?” said Robin with a trace of impatience.

“Hang on a minute,” said Strike, looking up at her. “Why was Theo standing outside the phone box?”

“What?” said Robin, confused.

“I don’t think we can doubt, now, can we, that Ruby Elliot saw Theo by that phone box near Albemarle Way? Her description and Gloria’s tally exactly… so why was Theo standing outside the phone box?”

“She was waiting for the van to pick her up.”

“Right. But, not to state the bleeding obvious, the sides of the old red telephone boxes have windows. It was pissing down with rain. Theo didn’t have an umbrella, and Ruby said Theo’s hair was plastered down—so why didn’t she shelter in the telephone box, and keep watch for her lift? Clerkenwell Road’s long and straight. She’d’ve had a perfectly good view from that telephone box, and plenty of time to come out and show herself to the van driver. Why,” said Strike for the third time, “was she standing outside the phone box?”

“Because… there was someone in it?”

“That would seem the obvious explanation. And that phone box at the end of Albemarle Way would give you a view of the top of St. John’s Lane.”

“You think someone was lying in wait for Margot? Watching out from that phone box?”

Strike hesitated.

“Do me a favor and look up Fragile X syndrome?”

“OK… why?” said Robin, setting down her almonds and beginning to type.

“That phone box is at the end of the Athorns’ street.”

While Robin brought up the search results, Strike pulled the copy of Irene Hickson’s receipt toward him. It had the time 3:10 p.m. on it. Eating noodles, Strike was still looking at the slip of paper when Robin said, reading off her screen,

“‘First called Martin-Bell syndrome… the FMR1 gene on the X chromosome was sequenced in 1991’… Sorry, what exactly do you need?”

“What specific disabilities does it cause?”

“‘Social anxiety,’” said Robin, reading again, “‘lack of eye contact… challenges forming relationships… anxiety with unfamiliar situations and people… poor ability to recognize faces you’ve seen before,’ but ‘good long-term memory, good imitation skills and good visual learning.’ Men are more severely affected than women… good sense of humor, usually…‘can be creative, especially visually’…”

She looked around the computer monitor.

“Why d’you want to know all this?”

“Just thinking.”

“About Gwilherm?”

“Yeah,” said Strike. “Well, about the whole family.”

“He didn’t have Fragile X, though, did he?”

“No, I don’t know what Gwilherm’s problem was. Maybe just the Bennies.”

He didn’t smile as he said the name this time.

“Cormoran, what coincidences did you notice?”

Instead of answering, Strike pulled a couple of pages of police notes toward him and read through them again. Out of force of habit, Robin reached out for Talbot’s notebook, and turned to the first page. For a couple of minutes, there was silence in the office, and neither partner noticed any of the noises that were as familiar to them as their own breathing: the traffic rolling down Charing Cross Road, occasional shouts and snatches of music from Denmark Street below.

The very first page of Bill Talbot’s notebook began with untidy jottings of what Robin knew to be genuine evidence and observations. It was the most coherent part of the notes but the first pentagrams appeared at the very bottom of the page, as did the first astrological observation.

Robin re-read this final paragraph twice, frowning slightly. Then she set aside her bag of almonds to delve in the nearest box of police evidence. It took her five minutes to find the original police record of Ruby Elliot’s statement, and while she searched, Strike remained deeply immersed in his own portion of the notes.

I saw them beside a telephone box, two women sort of struggling together. The tall one in the raincoat was leaning on the short one, who was in a plastic rain hood. They both looked like women to me, but I didn’t see their faces. It looked to me like one was trying to make the other walk quicker.

Pulse now quickened, Robin set aside this piece of paper, got back onto her knees and began to search for the record of Ruby’s statement to Lawson, which took her another five minutes.

I saw them beside the two telephone boxes in Clerkenwell Green, two women struggling with each together. The tall one in the raincoat was trying to make the little one in the rain hood walk faster.

“Cormoran,” said Robin urgently.

Strike looked up.

“The heights are round the wrong way.”

“What?”

“In Ruby’s very first statement to Talbot,” Robin said, “she said, ‘I saw them beside a telephone box, two women sort of struggling together. The tall one in the raincoat was leaning on the short one, who was in a plastic rain hood. They both looked like women to me, but I didn’t see their faces. It looked to me like one was trying to make the other walk quicker.’”

“Right,” said Strike, frowning slightly.

“And that’s what Talbot wrote in his horoscope notes, too,” said Robin. “But that’s not how it should have been, if those two women were the Fleurys. Where’s that picture?”

“Box one,” said Strike, shoving it toward Robin with his real foot.

She crouched down beneath the desk and began searching the photocopied papers until she found the sheaf of newspaper clippings Strike had shown her, months previously, in the Three Kings.

“There,” said Robin. “Look. There.”

And there was the old picture, of the two women who’d come forward to say that they were Ruby’s struggling women: the tall, broad, younger woman with her cheery face, and her aged mother, who was tiny and stooped.

“It’s the wrong way round,” repeated Robin. “If Fiona Fleury had leaned on her mother, she’d have flattened her…” Robin scanned the few lines beneath the picture. “Cormoran, it doesn’t fit. Fiona says she was wearing the rain hat, but Ruby says it was the short woman who had the rainhat on.”

“Ruby was vague,” said Strike, but Robin could see his interest sharpening as he reached out for these pieces of paper. “She could’ve been confused…”

“Talbot never thought the Fleurys were the people Ruby saw, and this is why!” said Robin. “The heights were reversed. It was the taller woman Ruby saw who was unsteady, not the little one…”

“So how come she didn’t tell Lawson the Fleurys couldn’t be the people she saw?”

“Same reason she never told anybody she’d seen Theo? Because she’d been flustered by Talbot trying to force her to bend her story to fit his theories? Because she lost confidence in herself, and didn’t know what she’d really seen? It was raining, she was lost, she was panicked… by the time it got to Lawson, maybe she just wanted to agree she’d seen the Fleurys and be left alone?”

“Plausible,” admitted Strike.

“How tall was Margot?”

“Five nine,” said Strike.

“And Creed?” said Robin.

“Five seven.”

“Oh God,” said Robin quietly.