“Presumably because he didn’t think a woman could be the Essex Butcher?”

“Exactly.”

Strike pulled his own notebook out of his coat pocket and opened it to the pages he’d scribbled on Tuesday.

“Irene’s first statement, which she gave to Talbot, said she’d had a grumbling toothache for a few days before Margot disappeared. Her friend Janice the nurse thought it might be an abscess, so Irene made an emergency appointment for three o’clock, leaving the practice at two-thirty. She and Janice were planning to go to the cinema that evening, but Irene’s face was sore and swollen after having a tooth removed, so when Janice phoned her to see how the dentist’s had gone, and to check whether she still wanted to go out that night, she said she’d rather stay at home.”

“No mobile phones,” mused Robin. “Different world.”

“Exactly what I thought when I was going over this,” said Strike. “These days Irene’s mates would’ve expected a minute-by-minute commentary. Selfies from the dental chair.

“Talbot gave his officers to understand that he’d personally contacted the dentist to check this story, but he hadn’t. Wouldn’t put it past him to have consulted a crystal ball.”

“Ha ha.”

“I’m not kidding. Wait till you see his notebook.”

Strike turned a page.

“Anyway, six months later, Lawson takes over the case and goes systematically back through every single witness and suspect in the file. Irene told the dentist story again, but half an hour after she left him, she panicked and asked to see him again. This time she admitted she’d lied.

“There’d never been any tooth pain. She hadn’t visited the dentist. She said she’d been forced to do a lot of unpaid overtime at the surgery and resented it, and felt she was owed an afternoon off, so she faked toothache, pretended to have got an emergency appointment, then left the practice and went to the West End to do some shopping.

“She told Lawson that it was only when she got home—she was still living with her parents, incidentally—that it occurred to her that if she went out to meet Janice the nurse that evening, Janice might ask to see the place where the tooth had been extracted, or at least expect to see some swelling. So when Janice rang her to check they were still going to the cinema, she lied and said she didn’t feel up to it.

“Lawson gave Irene quite a hard time, judging from his notes. Didn’t she understand what a serious matter it was, lying to the police, people had been arrested for less, et cetera. He also put it to her that the new story showed she had no alibi for any point of the afternoon and evening, other than around half past six in the evening, when Janice rang her at home.”

“Where did Irene live?”

“Street called Corporation Row, which as it happens lies very close to the Three Kings, although not on the route Margot would have taken from the practice.

“Anyway, at the point alibis were mentioned, Irene became hysterical. She poured out a load of stuff about Margot having a lot of enemies, without being able to say who these enemies were, although she referred Lawson back to the anonymous letters Margot received.

“The next day, Irene went back to Lawson yet again, this time accompanied by her very angry father, who did her no favors by losing his temper at Lawson for daring to upset his daughter. In the course of this third interview, Irene presented Lawson with a receipt from Oxford Street, which was marked 3:10 p.m. on the day Margot disappeared. The receipt was for cash. Lawson probably took a lot of pleasure in telling Irene and her dad that all the receipt proved was that somebody had gone shopping on Oxford Street that day.”

“Still—a receipt for the right day, right time—”

“Could’ve been her mother’s. A friend’s.”

“Why would they have kept it for six months?”

“Why would she?”

Robin considered the matter. She regularly kept receipts, but these were matters of expenses while doing surveillance, to be presented to the accountant.

“Yeah, maybe it is odd she still had it,” she conceded.

“But Lawson never managed to get anything further out of her. I don’t think he genuinely suspected her, mind you. I get the impression he just didn’t like her. He pressed her very hard on the anonymous notes she claimed to have seen, the ones mentioning hellfire. I don’t think he believed in them.”

“I thought the other receptionist confirmed she’d seen one?”

“She did. Nothing to say they weren’t in cahoots, though. No trace of the notes was ever found.”

“But that’d be a serious lie,” said Robin. “With the fake dental appointment, I can see why she fibbed and why she’d have been frightened to admit it afterward. Lying about anonymous notes in the context of a missing person, though…”

“Ah, but don’t forget, Irene was already telling the story of the anonymous notes before Margot went missing. It’s more of the same, isn’t it? The two receptionists could’ve invented these threatening notes for the pleasure of starting a malicious rumor, then found it impossible to back away from the lie after Margot disappeared.

“Anyway,” said Strike, flicking over a couple of pages, “so much for Irene. Now for her best buddy, the practice nurse.

“Janice’s original statement was that she drove around all afternoon, making house calls. The last visit, which was to an old lady with multiple health issues, kept her longer than she expected. She left there around six and hurried straight to a call box to ring Irene at home, to see whether they were still on for the cinema that evening. Irene said she didn’t feel up to it, but Janice had already got herself a babysitter, and was desperate to see the movie—James Caan, The Gambler—so she went anyway. Watched the movie alone, then went back to the neighbor’s, picked up her son and went home.

“Talbot didn’t bother to check any of this, but a zealous junior officer did, on his own initiative, and it all checked out. All the patients confirmed that Janice had been at their houses at the right times. The babysitter confirmed that Janice returned to pick up her son when expected. Janice also produced a half-torn ticket for the movie out of the bottom of her handbag. Given that this was less than a week after Margot disappeared, it doesn’t seem particularly fishy, her still having it. On the other hand, a torn ticket is no more proof that she sat through the movie than the receipt is proof Irene went shopping.”

He threw his cigarette end out of the window.

“Where did Janice’s last patient of the day live?” asked Robin, and Strike knew that her mind was running on distances and timings.

“Gopsall Street, which is about a ten-minute drive from the practice. It would’ve been just possible for a woman in a car to have intercepted Margot on the way to the Three Kings, assuming Margot was walking very slowly, or was delayed somewhere along the route, or left the practice later than Gloria said she did. But it would’ve required luck, because as we know, some of the path Margot would’ve taken was pedestrianized.”

“And I can’t really see why you’d make arrangements with a friend to go to the cinema if you were planning to abduct someone,” said Robin.