It was an assassination method the Russians had perfected, the bullet soft-nosed and lightly packed, from an adapted Tokarev automatic. There had been no exit wound, just an instantaneous explosion of the heart. The photograph showed no distortion of the features: the dead man looked as if he might awaken at any moment, just like the others had done. Sir Alistair Wilson was surprised at that. He would have expected an expression of pain. The intelligence director pushed the latest file away, knowing there was nothing he could learn from it. Delhi, Ankara and now Bangkok: and he was no closer to the traitor now than he had been six months ago, when the killings of embassy intelligence Residents started.

Wilson felt impotent, having to rely so completely upon Alexander Hotovy. The man’s defection from the Czech embassy in London had been agreed when the assassinations began. And was immediately postponed, for Hotovy, a major in the Statni Tajna Bezpecnost, the Czech intelligence service, to earn his asylum by discovering how the British operatives were being pinpointed. The initial response had been encouraging: perhaps too much so. Within a week, Hotovy confirmed that all Eastern bloc embassies were receiving, via Moscow, details of British cabinet guidance to overseas ambassadors, together with personnel details from which it was easy to isolate intelligence officers in the field. Then came the stalemate. By the time the guidance arrived from Russia, all indication of original source had been removed. Which meant Wilson knew he had a spy in a British embassy somewhere in the world, but not which one. The trap had seemed feasible, even clever, when he devised it. That had been six months before and since then two more people had died.

The irritation of his own ineffectiveness was showing on Wilson’s face when he looked up at his deputy’s entry.