Knox marched through the front door of Leconfield House, full of righteous indignation. After security reluctantly waved him through, he made his way across the ground floor’s large typing pool to the bank of lifts that would take him up to confront Manning. By now the MI5 rumour mill had done its work and row after row of people averted their eyes as he passed. Colleagues he’d worked with for over a decade pretended they couldn’t see him, but he didn’t care. He was about to give them something new to talk about.

Knox hadn’t needed another trip down to see White or up to Cambridge to confirm that the new papers he’d found in Bianchi and Moretti’s flat were legitimate and dangerous. He’d looked through the papers when he’d got back to Kemp House, and a couple of the equations felt familiar, though he couldn’t remember where from. In the morning he took them to the library in Senate House, the towering grey obelisk that loomed over Bloomsbury, and ten minutes in the physics section jogged his memory: they were a set of radio wave frequency calculations.

Knox had gleaned enough from briefings with White to know that frequency identification was a fundamental part of the science behind Operation Pipistrelle. Now the Italians were no longer just a mystery for Knox to solve; they were a potential threat to national security, and the timing of their deaths was suddenly extremely significant.

The OECD was the direct descendant of the Organisation for European Economic Co-operation, which had been formed to administer the thirteen billion dollars America and Canada pumped into Europe after the war via the Marshall Plan.

After the continent’s economies were shored up, the OEEC’s members decided to expand both the organisation and its remit. America and Canada were allowed to join, a belated thank you for their money, and the members magnanimously decided that the new OECD’s mission would be to help the world’s less-developed economies grow and prosper. Whether these economies wanted this help was a detail that would be ironed out later.