She led Vanessa through the sitting room, past Sarah and Matthew, who were now mocking Tom’s baldness to his face.

The rear wall of the small courtyard garden was covered in ivy. Well-maintained shrubs stood in terra-cotta tubs. Robin, who did not smoke, had put ashtrays and a few fold-up chairs out there, and dotted tea candles around. Matthew had asked her with an edge in his voice why she was taking so much trouble over the smokers. She had known perfectly well why he was saying it and pretended not to.

“I thought Jemima smoked?” she asked, with a feigned air of confusion. Jemima was Matthew’s boss.

“Oh,” he said, caught off balance. “Yeah—yeah, but only socially.”

“Well, I’m pretty sure this is a social occasion, Matt,” said Robin sweetly.

She fetched Vanessa a drink and came back to find her lighting up, her lovely eyes fixed on Sarah Shadlock, who was still mocking Tom’s hairline, with Matthew her hearty accomplice.

“That’s her, is it?” Vanessa asked.

“That’s her,” said Robin.

She appreciated the small show of moral support. Robin and Vanessa had been friends for months before Robin had confided the history of her relationship with Matthew. Before that they had talked police work, politics and clothes on evenings that took them to the cinema, or to cheap restaurants. Robin found Vanessa better company than any other woman she knew. Matthew, who had met her twice, told Robin he found her “cold,” but said he could not explain why.

Vanessa had had a succession of partners; she had been engaged once, but broken it off when he had cheated. Robin sometimes wondered whether Vanessa found her laughably inexperienced: the woman who’d married her boyfriend from school.

A few moments later, a dozen people, colleagues of Matthew’s with their partners, who had obviously been to the pub first, streamed into the sitting room. Robin watched Matthew greeting them and showing them where the drinks were. He had adopted the loud, bantering tone that she had heard him using on work nights out. It irritated her.

The party quickly became crowded. Robin effected introductions, showed people where to find drink, set out more plastic cups and handed a couple of plates of food around because the kitchen was becoming packed. Only when Andy Hutchins and his wife arrived did she feel she could relax for a moment and spend some more time with her own guests.

“I made you some special food,” Robin told Andy, after she had shown him and Louise out into the courtyard. “This is Vanessa. She’s Met. Vanessa, Andy and Louise—stay there, Andy, I’ll get it, it’s dairy-free.”

Tom was standing against the fridge when she got to the kitchen.

“Sorry, Tom, need to get in—”

He blinked at her, then moved aside. He was already drunk, she thought, and it was barely nine o’clock. Robin could hear Sarah’s braying laugh from the middle of the crowd outside.

“Lemmelp,” said Tom, holding the fridge door that threatened to close on Robin as she bent down to the lower shelf to get the tray of dairy-free, non-fried food she had saved for Andy. “God, you’ve got a nice arse, Robin.”

She straightened up without comment. In spite of the drunken grin, she could feel the unhappiness flowing from behind it, like a cool draft. Matthew had told her how self-conscious Tom was about his hairline, that he was even considering a transplant.

“That’s a nice shirt,” said Robin.

“Wha’ this? You like it? She bought it for me. Matt’s got one like it, hasn’t he?”

“Er—I’m not sure,” said Robin.

“You’re not sure,” repeated Tom, with a short, nasty laugh. “So much f’ surveillance training. You wanna pay more attention at home, Rob.”

Robin contemplated him for a moment in equal amounts of pity and anger, then, deciding that he was too drunk to argue with, she left, carrying Andy’s food.

The first thing she saw as people cleared out of the way to let her back into the courtyard was that Strike had arrived. He had his back to her and was talking to Andy. Lorelei was beside him, wearing a scarlet silk dress, the gleaming fall of dark hair down her back like an advertisement for expensive shampoo. Somehow, Sarah had inveigled her way into the group in Robin’s brief absence. When Vanessa caught Robin’s eye, the corner of her mouth twitched.

“Hi,” said Robin, setting the platter of food down on the wrought iron table beside Andy.

“Robin, hi!” said Lorelei. “It’s such a pretty street!”

“Yes, isn’t it?” said Robin, as Lorelei kissed the air behind Robin’s ear.

Strike bent down, too. His stubble grazed Robin’s face, but his lips did not touch skin. He was already opening one of the six-pack of Doom Bar he had brought with him.

Robin had mentally rehearsed things to say to Strike once he was in her new house: calm, casual things that made it sound as though she had no regrets, as though there were some wonderful counterweight that he couldn’t appreciate that tipped the scales in Matthew’s favor. She also wanted to question him about the strange matter of Billy and the strangled child. However, Sarah was currently holding forth on the subject of the auction house, Christie’s, where she worked, and the whole group was listening to her.

“Yeah, we’ve got ‘The Lock’ coming up at auction on the third,” she said. “Constable,” she added kindly, for the benefit of anyone who did not know art as well as she did. “We’re expecting it to make over twenty.”

“Thousand?” asked Andy.

“Million,” said Sarah, with a patronizing little snort of laughter.

Matthew laughed behind Robin and she moved automatically to let him join the circle. His expression was rapt, Robin noticed, as so often when large sums of money were under discussion. Perhaps, she thought, this is what he and Sarah talk about when they have lunch: money.

“‘Gimcrack’ went for over twenty-two last year. Stubbs. Third most valuable Old Master ever sold.”

Out of the corner of her eye, Robin saw Lorelei’s scarlet-tipped hand slide into Strike’s, which had been marked across the palm with the very same knife that had forever scarred Robin’s arm.

“Anyway, boring, boring, boring!” said Sarah insincerely. “Enough work chat! Anyone got Olympics tickets? Tom—my fiancé—he’s furious. We got ping pong.” She pulled a droll face. “How have you lot got on?”

Robin saw Strike and Lorelei exchange a fleeting look, and knew that they were mutually consoling each other for having to endure the tedium of the Olympics ticket conversation. Suddenly wishing that they hadn’t come, Robin backed out of the group.

An hour later, Strike was in the sitting room, discussing the England football team’s chances in the European Championships with one of Matthew’s friends from work while Lorelei danced. Robin, with whom he had not exchanged a word since they had met outside, crossed the room with a plate of food, paused to talk to a redheaded woman, then continued to offer the plate around. The way she had done her hair reminded Strike of her wedding day.

The suspicions provoked by her visit to that unknown clinic uppermost in his mind, he appraised her figure in the clinging gray dress. She certainly didn’t appear to be pregnant, and the fact that she was drinking wine seemed a further counter-indication, but they might only just have begun the process of IVF.