Next she took a look at the papers piled on top of the boxes. It was all household stuff as far as she could tell: utility bills, bank and credit card statements, dating back years.

Leafing through them exposed the lid of one of the boxes in the corner. Suddenly, as her glance slid across it, Wada froze. Somebody had written on the box with a black felt-tipped pen:

サリン

Sarin. In Japanese katakana.

For a moment, Wada couldn’t seem to breathe. She stepped back and stared at the characters. She’d seen them often enough, in newspaper reports following the Tokyo subway attack and later coverage of the trials of Shoko Asahara and other members of the Aum Shinrikyo cult. サリン. Sarin. The cause of her husband’s death and the deaths of many other husbands like him. But that was far away. That was in Japan. What did that have to do with Martin Caldwell? Why did this Englishman have a box with the word written on it – in Japanese?

She pulled the box out and crouched down beside it. Originally it had evidently contained twelve bottles of Cossack vodka. There were remnants of Sellotape on the folded-together flaps and, in faded red lettering, the rubber-stamped demand Ban the Bomb. Plus those three Japanese katakana that could only have one meaning. Written by hand. Written by someone who knew the language. Caldwell? Or Peter Evans, Shitaro Masafumi’s translator? Was that how Caldwell knew Evans? Because they’d been friends?

Wada prised the flaps apart and looked in. The box was full of papers and documents. She began leafing through them. There were lots of photocopied newspaper cuttings dating from the 1970s, mostly from a paper called the Western Morning News, written by a reporter called Barry Holgate. There was too much material to take in at a glance, but various words sprang out at her: nerve gas; chemical warfare; sarin. Several of the headlines referred to somewhere called Nancekuke. Some of the articles included grainy photographs of industrial buildings in an isolated, coastal location and, in one case, a photograph of a sign attached to a chain-link fence: MINISTRY OF DEFENCE CDE NANCEKUKE RESTRICTED ENTRY PERMITS MUST BE SHOWN CAMERAS NOT PERMITTED. There was a map as well, folded over to show a stretch of coastline with the runways of an airfield marked out near a village called Porthtowan.