On her long subway journey home that night, Wada found herself thinking about the Nishizaki connection in the case more and more. There’d been something in Kodaka’s tone of voice when he spoke of him that suggested he knew a little more about Nishizaki than he was willing to disclose. He often kept information to himself and there were things he did Wada was happy to know nothing about. For that matter, there were innumerable cases he’d handled before Wada started working for him that might for all she knew have involved Nishizaki. Sokaiya were a specialty of Kodaka’s. And Mrs Takenaga had alleged that Nishizaki had once been sokaiya himself. Wada didn’t feel entirely certain she was being told all she needed to know. Which, rather to her surprise, she found more intriguing than disturbing.

At her small apartment, she consumed a frugal supper and then, ignoring Kodaka’s advice, immediately went online to see if there was an accessible digital archive for the London Evening Standard.

The result was frustrating. It seemed she could view copies dating from 1892, but 1992 was a different matter. Physical copies of papers could be inspected at the national newspaper archive, but that wasn’t in or even near London. She abandoned the effort and moved on to more straightforward matters, starting with the booking of a flight. She found a seat on an eleven o’clock Monday morning departure, with flexible return dates. Next she booked herself a room for four nights at the Envoy Hotel, chosen because it was the hotel where, according to Mrs Takenaga, the tour party had been staying at the time of Shitaro Masafumi’s death back in 1977. Now she was set.

Normally a sound sleeper, Wada woke several times that night and eventually rose early but by no means refreshed. Meditating, which she tried to do every morning, proved almost impossible. She decided to go in to the office.

She’d been planning to spend a few hours there anyway, albeit later in the day, to clear a few administrative tasks she’d otherwise have attended to in the week ahead. Peace reigned in Nihonbashi on a Saturday morning in spring. Birds skittered and chirped in flight. The air seemed to sparkle. Now she was up and doing something, she felt calmer, more in charge of herself.

The lobby of the office building was quiet, the porter behind the desk registering surprise at her arrival with the merest twitch of his eyebrows. She smiled and said good morning. He returned the greeting.

Then, as she approached the lift, there was a ping, the doors slid open and Kazuto Kodaka stepped out.

It was at once obvious to Wada he hadn’t expected to see her. There was a flinch of dismay before he reordered his expression. ‘Wada,’ he said. ‘Back so soon?’

‘I have rather a lot to attend to.’