Then Janice began to laugh hysterically. It was a great picture.

* * *

Mullen staggered down the seven steps to the pavement and heaved the box unceremoniously into the boot. This one contained a significant part of his worldly goods, though few of them had any financial or emotional value. A small selection of cutlery, three tasteless mugs, two saucepans, a tray, a small LED desk lamp, a tin decorated with a Dickensian Christmas scene (and containing just four tea bags), cling film, refuse bags and so on. The rear section of his tired old Peugeot was already jam-packed with two cases, two other boxes and several plastic bags. He believed in minimal possessions, and it was ridiculous how much clobber he had collected since his return to the UK. There were a few more bags still waiting to be shifted out of his miserable flat, but that would then be that.

“Excuse me.”

Mullen turned and found himself faced by a woman.

Cute! That was his first thought, though he wasn’t stupid enough to say so. She had dark curly hair, a round face, a single mole on her right cheek and grey-green eyes that looked right into his — and maybe beyond. She was, he reckoned, about thirty. Maybe this was his lucky day.

“Are you Doug Mullen?”

“I am.”

“This Doug Mullen?” She held up one of his business cards.

He nodded. He was wondering how she knew to find him here when his card carried only a website, email address and mobile number.

“Janice recommended you,” she said, still giving him the deep-stare treatment. Janice. Whom he had last seen in the Cricketers Arms, misery personified, with the photos of her husband in one hand and an empty glass in the other. To whom he had made his excuses and left for a pressing job that wasn’t pressing at all. In point of fact, there hadn’t been any job, pressing or otherwise, since then, but Mullen was barely admitting that to himself, let alone to the woman who stood in front of him, appraising him. He wondered how many marks out of ten she was giving him.

“I’m Rose Wilby.” She held out her hand. Mullen took it, holding on for slightly longer than was necessary. She glanced at the car. “Are you doing a runner?”

“Moving house.”

“So you’re not doing a bunk before some unhappy husband comes to get you?”

Mullen gave his default shrug. “Somewhere cheaper — and larger.”

“Larger? It can’t be Oxford then. Where on earth is it? Outer Mongolia?”

“Boars Hill.” Mullen watched her eyes widen. Was it surprise or disbelief? Or both? Not that it was a big deal what she thought, he told himself. But not for the first time in his messy life Mullen was telling himself one thing and believing another. The truth was that attractive women never accosted him in the street, and he wanted it to last for a bit longer. “I’m house-sitting,” he said. “For a professor.”

Rose gave a curious smile, one side of her mouth slightly higher than the other, as she assessed his excuse-cum-explanation for the fact that he was moving to Oxford’s poshest postcode.

“It’s ridiculous really. He pays me to live in his large house while he takes a sabbatical with his wife in the States. Mind you, there’s a lot of garden to look after and some DIY he wants me to do as part of the deal, but frankly . . .”

She smiled again, this time as if genuinely amused. Mullen dribbled to a halt.

“Any nice wardrobes to explore?”

Mullen was puzzled. Was she flirting?

“C S Lewis? Narnia?”

Mullen could see he had disappointed her. He was suddenly back at school, standing up in front of the class, having failed some critical test.

Rose persisted. “The Lion, the Witch and the Wardrobe. It’s a book. The house is owned by a professor.”

He finally got the reference. “I’ve seen the film.” He had watched it on TV with his niece Florence. He had rather liked it, except for the bit where Father Christmas appeared. That had seemed odd to him.

Mullen could see that having watched the film was clearly not, as far as Rose Wilby was concerned, in the same league as having read the book. “It’s my favourite book ever,” she said. There was a pause as each of them considered the chasm that lay between them. “I know!” Her earnest face brightened. “I’ll lend you my copy, as long as you promise to return it. Everyone should read it.”

“Thank you.” He didn’t know what else he could say.

“It will appeal to the child in you.”

“What makes you think there is a child in me?” He grinned. This was him flirting back.

But it didn’t have the desired effect. The crooked smile on her face faded into invisibility. “You’re a man, aren’t you? And so by definition you’re a little boy at heart.”

“If you say so.”

“Oh I do.”

They stood facing each other for several seconds, this time in an enforced conversational silence as an ambulance tore past, siren blaring.

“I’d ask you in for a coffee,” he said trying to put things right, “but it’s all packed and I really need to get this car moved before the traffic warden comes calling.”

“I need to talk to you about a job.”

“Your husband, is it?”

She laughed. She held up her left hand, showing him her fingers. Not a ring in sight. “What sort of private investigator are you?”

* * *

Professor Thompson’s house was all you might expect of Boars Hill — and more. A sweeping gravel entrance and an honour guard of trees accompanied visitors — in this case Doug Mullen and Rose Wilby — right up to an imposing Edwardian edifice. Rose ran a curious eye over the façade. She looked up to the third storey, where large latticed windows peered out from under the steeply pitched roofs. It was easy to imagine that there might be a wardrobe inside which offered a secret entrance to another world. Not that C.S. Lewis had lived in Boars Hill. She knew that because she had visited his house in Risinghurst. Lewis’s home was an altogether much less imposing structure than this one. In some ways she had found it rather disappointing, not least because so much of the original three acres of garden had long since been sold off for development.

“Do you mind if I have a snoop around?” she asked as soon as he had unlocked the oak front door.

She didn’t wait for his answer, heading straight up the stairs to the bedrooms, where she took in each room like an estate agent assessing a house for a quick valuation. Downstairs again, as Mullen began to bring his boxes and bags in, she admired the sitting room, the dining room, another sitting room and finally the spacious kitchen with walk-in larder.

The professor — or rather, she suspected, the professor’s wife — had left a considerable supply of tinned and dry goods in the larder. She wondered if Mullen was free to raid their supplies as he liked. Returning to the kitchen, she filled and switched on the kettle, located tea bags and mugs and found a fresh pint of milk sitting unopened in the fridge.

Two minutes later they were sitting down in the kitchen at either end of a long oak table.

“Janice was full of praise for you,” she said. It wasn’t entirely true. Janice had said he was very good at tracking her husband, though she had only admitted this after she had got her to promise on the Bible not to reveal this to anyone. But Janice had been much less complimentary about other aspects of Mullen. “Morally unreliable if you ask me,” had been one of her comments. And, “I bet he looks at himself in the mirror every morning.” Which had only caused Rose to wonder whether Janice had made a pass at him and been rebuffed.

“This is a slightly different job from tracking an errant husband,” she continued. “I want you to find out what happened to a friend of mine called Chris.” Her grey-green eyes saw his blue ones blink in surprise.

“They found him floating face down in the River Thames. Bloodstream full of alcohol. Fell in drunk and drowned.” She paused again, wondering if Mullen would admit to knowing Chris. This was a test. Pass or fail. Right or wrong.