“Yes. I did.”

“Is he the only person you’ve been questioning about me?”

“Actually, no. I spoke to your family.”

“Did you? They haven’t mentioned it.”

“Perhaps they didn’t think there was any need to.”

“Perhaps not. Mind explaining why you went to them?”

“Not at all. It’s why I came. To explain.” I tried to smile, but only succeeded in producing a tight-lipped grimace. “I just wanted to confirm your story… to check some of the details… before the police became involved.”

“Why? Don’t you think they’ll do a thorough job?”

“It’s not that. I…”

“You don’t doubt the truth of what I told you?”

“No.” I said, happy to be able to answer honestly. “I don’t.”

“Then what are you trying to accomplish?”

I shrugged. “Absolute certainty, I suppose.”

He pushed himself upright, walked to the window where I was standing and leant against the sill. He rested his head against the glass and looked at me thoughtfully. “Who put you up to this, Robin?”

“Nobody.”

“Sir Keith?”

“I told you. Nobody.”

“Sarah, then. If so, she’s disappointed me. I should have thought a lawyer would prefer to handle such things personally.”

“Sarah has no idea what I’ve been doing.”

“It must be Bella in that case.” He raised his head from the glass and clicked his tongue. “Yes. On reflection, it has to be Bella. She’d always ask whether something was deniable before she wondered whether it was true. What does she have on you that obliges you to act as her errand-boy?” Before I could reply, he’d moved back across the room and slumped down into an armchair, his arms still firmly crossed, his brow still quizzically furrowed. “Don’t bother to answer. It’s really none of my business. Besides, I don’t mind you questioning whoever you please. I’ve nothing to hide. If you can persuade my mother to face the truth about me, or Sir Keith the truth about Louise, so much the better. They’ll have to do so eventually. As for Bella, she can do as she pleases as far as I’m concerned. So can you. The police will subject my statement to far closer and more critical scrutiny than you’ll be able to. But the result will be the same. In a few months from now, you’ll have what you claim to want. Absolute certainty.”

“Perhaps I can have it now.”

“Be my guest.”

“Your mother thinks you sent her a postcard of Mont Blanc. From Chamonix.”

“Mum remembers that, does she? Well, well, well. I did, as it happens. But not from Chamonix. I bought it in Chambéry, where I got off the train from Lyon. Posted it before getting the next train back. Thought it might help to cover my tracks. Said I was in Chamonix, of course. ‘A few lines as I sit in a cable-car being winched up Mont Blanc.’ That sort of thing. Dated it the following day. There was no chance of Mum making much sense of a blurred French postmark. I thought it might come in useful. Hasn’t she got it, then?”

“No.”

“Well, it doesn’t make much difference. It’s just another of those little details. The police will go through them all with a fine-tooth comb.”

“It can’t do any harm for me to check a few of them myself, can it?”

“None whatever.” He shook his head and looked at me intently. “But do me a favour, will you? Tell Bella it won’t work. I’ve set my course and nothing’s going to blow me off it. The sooner you and she and everyone else involved confronts what that means for them, the less painful it will be when the truth comes out. As I mean to make sure it does.”

I’d intended to set off back to Petersfield as soon as I left Bathurst Wharf. But when it came to the point, a long and solitary rail journey, with an empty house waiting at the end of it, didn’t appeal. Whereas a walk out to Clifton and an impromptu visit to Sarah did. I badly needed to discuss my difficulties with somebody and she was about the only person I could rely on being at all sympathetic.

There was another reason for seeing her, as I admitted to myself over a pint in a pub just round the corner from her flat, where I stopped off to give her time to get home from work. Sooner or later, she was going to find out what I’d been up to. Paul would probably tell her the next time they met, whenever that might be. It was even possible his parents might contact her, or she them. Either way, I couldn’t take the risk of her alerting Sir Keith to my activities on Bella’s behalf. It seemed altogether wiser to enlist her in our conspiracy of silence without delay.

I waited until I was confident she’d be back before leaving the pub. In the event, I nearly waited too long, because, when I arrived, she was clearly preparing to go out for the evening. She was looking unusually glamorous, in a short black dress adorned with discreet jewellery. And her hair had a lustre to it that suggested it had been professionally styled that very day.

“Robin! What brings you here?”

“It’s a long story. Do you have time to hear it?”

“I’m afraid not. Rodney’s picking me up in about twenty minutes.” The news that Rodney was still on the scene set my teeth on edge. “He’s taking me to a party. And since it’s being thrown in my honour, I can’t really arrive late, can I?”

“In your honour? What’s the occasion?”

I was momentarily afraid Rodney’s persistence might have lured Sarah into an engagement to marry him. So I was mightily relieved when she replied: “This is the last day of my articles. As of tomorrow, I shall be a fully fledged lawyer.”

“Really? Well, congratulations.”

“Thanks.”

“Will you be staying on at Anstey’s?”

“For the time being. Until something better turns up, anyway. If it turns up. To be honest, I can’t help wondering whether my connection with a miscarriage of justice, however remote it may be, will have some effect on my career prospects. Learning the truth from Paul was like grasping a cactus. You just can’t tell how deep some of the spines may sink.”

I smiled consolingly. “You could say that’s why I’m here.”

“I thought it probably was.” She glanced at her watch. “Look, twenty minutes is twenty minutes. Do you want a drink?”

“Thanks. I think I do.”

Perhaps the constraint on time made it easier. Obliged to be swift, I was also succinct, holding back none of the discreditable aspects of my dilemma. What would have been the point? Sarah knew Bella’s nature as well as I did. And she also knew how insoluble my problem was.

“Well,” she said when I’d finished, “I certainly won’t say anything to Daddy. But I still don’t understand what Bella’s trying to achieve. She doesn’t seriously think Paul’s lying, does she?”

“No. I don’t believe she does.”

“Then what’s she hoping you’ll turn up?”

“Grounds for legitimate doubt, I suppose.”

“But so far you’ve drawn a blank?”

“Yes. As complete as it was predictable.”

“Which leaves you in a genuine quandary. How to let Bella down without provoking her into a breach of your agreement.”

“Exactly.”

“That’s tough.” She crossed to the window and looked down into the darkening street. But there was evidently no sign of Rodney. “As a lawyer, I ought to be able to give you some good advice. I’m not sure I can, though.” She turned round and shrugged. “I’m sorry you should have been dragged into this, Robin. You don’t deserve to have been.”

“It’s not your fault.”

“Maybe not. But I’m still sorry.”

“Sounds as if you think I should just give up.”

“I suppose I do. The police will take a microscope to every detail of Paul’s story. If there’s a flaw to be found, they’ll find it.”

“But Bella’s not prepared to wait for them. Which would be her problem, except…”

“It’s yours.” Sarah shook her head and sighed. She seemed about to speak when a car drew up outside and sounded its horn. She glanced out, smiled and waved. “That’s Rodney,” she said to me over her shoulder. “I must go.”