That had to be some kind of milestone, even though, in a sense, he’d done most of his mourning before she’d actually died, just after Christmas. And she wouldn’t have wanted him to feel guilty about moving on with his life. No longer having to worry about her condition, her prognosis – how much of a future she had and how it was going to end – was a relief he hardly wanted to acknowledge, even to himself, though she’d told him that was how it would be. She’d worked as a psychotherapist, after all. She’d known how such things worked.

‘I’m OK, Caro,’ he murmured. She’d weaned him off ‘Mummy’ when he was about ten and insisted, in keeping with her New Age principles, on his using her first name. He took a deep breath of the crisp river air as he pictured her smile in his mind’s eye. ‘Forty-one and a stone overweight. But OK.’

Most of the passengers still aboard left with Nick at Greenwich. He headed for the shops, bought the cheese and wine, then ambled through the grounds of the old Royal Naval College and crossed Trafalgar Road. He was in no hurry. Whether Kate was home or not, he anticipated a late supper, in the kitchen, relaxing and swapping expectations for their different weeks ahead.

Greenwich Park rose ahead of him, long shadows stretching across its grassy slope, as he walked along Greenwich Park Street towards home. He led a privileged life. He knew that. Without Kate’s family money they’d never be living in such a lovely part of London. The park, the college, the river. There was nothing to dislike about Greenwich except the hordes of tourists. Caro had often reminded him just how privileged he was. And, if she didn’t, April, her partner of forty years, could be relied on to do it for her. Well, at least she was still there in his life to chip away at any signs of complacency.

He bounded up the steps to the yellow front door of their Georgian house and let himself in. The beeping of the alarm and the slew of post on the mat told him Kate wasn’t home yet. No surprise, really. He silenced the alarm and carried the shopping into the kitchen, where he noticed the green message button flashing on the landline phone as he stood the carrier bag on the marble worktop. He went back to the front door to collect the post, then returned to the kitchen, sifting through the envelopes as he went. None of it looked very interesting.

He pressed the button on the phone. There was only one message, which, subconsciously, he assumed would be something trivial, since he’d have heard about anything important via his smartphone.

‘Nick, this is … Martin Caldwell.’