And what was he to make of Paul and Janice Atkinson? No sign of marital disharmony there. But then what did he expect? If you’re having an affair and your marriage is on the verge of going down the pan, that doesn’t mean you don’t put on shows of unity. But Janice’s arm was tucked through Paul’s and there was a broad smile on her face; either it was a very brave bit of play-acting or she didn’t at that stage have a clue about his affair. Except that this took place only a week or so before she had contacted Mullen and hired him to track her husband.

And then there was Margaret Wilby, glaring out of the background as if this was the last place on earth she wanted to be. Why was she there if that was the case? Was she there out of duty, under sufferance? Or had there been some falling out with someone earlier that evening?

Mullen clicked the screen of his laptop down and stood up. He felt confused and frustrated, not just with the overload of thoughts, but with the attitude of DI Dorkin. He clearly thought that the anonymous threatening call which Mullen had told them about was fiction, whereas Mullen could still hear the voice of the man in his head, telling him that one of his friends would pay the price. What did he mean by that? Presumably that he was prepared to kill again if Mullen didn’t give up his investigation. Who were the friends he was threatening? He had only been in the area a few months and there were few (if any) people he could genuinely call friends. Rose? Possibly. Becca? He guessed so. Kevin Branston? Mel or Brian or Jean or any of the other volunteers at the Meeting Place? They were all nice to him and twice they had all had a drink together after the evening sessions. What about Pavel from the Iffley Road flats? Ultimately it depended on what the caller meant by ‘friend.’

* * *

In the end Mullen decided he had had enough and made his way into the garden. He thought he’d check the tomato plants for water, weed the vegetable patch and tidy up generally. It would help him to switch his brain off for a while and when he had finished he would take a few photographs so that the professor could see that he was looking after the place. But he had barely got his hoe out before he heard a car pull into the drive. There was a wild attention-grabbing hooting. So whoever it was, it wasn’t the police again. He straightened up and walked round the side path, carrying his hoe. It wouldn’t hurt to show he was in the middle of something.

It was Becca Baines. She grinned. “Ah, it’s the hired gardener.” She held up two bags. “Lunch! Nice and healthy: salad and fresh rolls, plus strawberries for pudding.”

Mullen realised with a start that he was pleased to see her — and also hungry. But he was puzzled that she hadn’t rung first. “I might have been out,” he said.

“In that case I would have eaten solo in your lovely garden and then sunbathed until it was time to go to work.” She smiled. “I’m on the night shift today.”

They ate at the teak garden table, half in the shade and half out. They talked easily. Or rather Becca talked while Mullen listened. Not that he minded. She was good, lively company. Eventually they finished and he went inside to make them coffee. She followed with the debris of lunch.

“You seem distracted,” she said as she put the leftovers in the fridge.

“Sorry.”

“Well are you going to tell me about it or do I have to apply Chinese burns to extract the information?”

So Mullen started to talk. About Chris, about Janice, about the police’s questioning that morning and about what he had seen on Facebook. The only thing he didn’t mention was the anonymous caller.

“Show me,” she said. So he did.

He took her through each photograph, telling her who he knew in each one. She was silent now, murmuring occasionally, sipping her coffee, taking it all in. When he got to the end, he turned and looked at her. “Any thoughts?”

“There are more shots of your glamorous vicar friend than anyone,” she said.

“Yes.”

“And no wedding ring on her finger.”

“No.”

“Is she gay?”

“I don’t know.”

“I bet she isn’t.” Becca had taken over the laptop. She moved back to one of the photographs of Diana Downey, mouth open, laughing, surrounded by punters. “Look at her. She likes to be the centre of male attention. A bit of a prick-teaser, if you ask me. Hiding behind her clerical robes.”

Mullen almost pointed out that she didn’t seem to wear ‘clerical’ clothes even in church, but managed not to.

“Who took the photos?” Becca said.

“Sorry?” Mullen was taken off guard by the change of direction. “I don’t know.”

“A man, I bet. Probably fancies her something rotten.”

It was a light bulb in the brain moment for Mullen. Of course! It was so obvious. Kevin Branston! It all made sense. Branston was conspicuously absent from the photographs, so the chances were that it was him taking the photos. And it was Branston who had been leaving Diana Downey’s house in something of a hurry before Mullen’s own appointment with her. He was probably in charge of the Facebook account too, making sure there were plenty of photos of their open evening on display — not to mention Reverend Downey in all her glamour. He was besotted with her. The question was: did she feel the same way about him?

“Well?” Becca was looking at him impatiently. “What’s going on in that tiny little brain of yours? Because I can hear the cogs clicking, albeit rather slowly.”

Mullen explained. Becca listened with a brow so furrowed it might have been a freshly ploughed field. He thought he found her even more attractive when she was in serious mode. When he had finished, he waited for her to respond. He needed help and he reckoned that she — being a woman and detached — might be the person to provide it.

“I suppose the question is: does the vicar getting up to a bit of hanky-panky with your boss have any relevance to the two deaths?”

“It’s possible, I suppose. If someone was trying to blackmail them, maybe . . .” Mullen dribbled to a halt. Just putting his thinking into words seemed to highlight how flimsy it was.

Becca was looking at him inscrutably. “You don’t seem very certain.”

“No.” He scratched his head. “Well, these days it wouldn’t be the end of the world if such a relationship came to light would it?”

“Is Kevin Branston married?”

Mullen felt very stupid. He hadn’t thought of that. But he knew the answer to her question. “He wears a wedding ring.”

“So put yourself in the Reverend’s shoes. She’s fallen for a married guy. They are sleeping together. Every Sunday she stands up in the pulpit and preaches the ten commandments and all that jazz. Then Chris and Janice find out and they decide to apply a bit of blackmail. ’Woman Vicar is a Marriage Wrecker!’ You can imagine the headlines in the Daily Trash, can’t you? So Reverend Downey tells Kevin it’s all over and she tells him why. But Kevin is obsessed with her. No way is he going to let her finish with him. He’s going to sort the two of them out permanently. So he arranges two very different ‘accidents.’ Maybe he doesn’t even tell Diana.”

She downed the last of her coffee and put her mug on the side. “Well?”

“OK,” Mullen said. “You’ve made a good case. But where’s the hard evidence?”

“You’re the private eye, buster.”

* * *

Mullen’s intention had been to get to the Meeting Place early and in some way or other confront Kevin Branston. He hadn’t worked out the details in his head when he left Boars Hill. But the road to hell is paved with good intentions, as the saying goes, especially on the Oxford ring road system on a Friday, when the rush hour begins midway through the afternoon and lasts forever — or so it seemed to Mullen as he sat fuming in his car on the slow drag towards the Heyford Hill roundabout.

So Mullen actually arrived five minutes late, which put him at an immediate disadvantage. Branston was onto him within seconds, even though he had tried to slip in unobtrusively.