At the rear of the long lab, he unlocked a heavy, soundproof security door and locked it behind him. He descended two flights of stairs and came out in a large room filled with cages. The soft glow of red stand-by lights cast an eerie pall over an enclosed area that he knew held around a hundred and thirty people.

He walked past them to his office, turned on his desk lamp and sat at his secured computer. The computer had no connection to a public or even a Pakistani government network. The B6 level of the secret facility held a server farm with a manually upgraded scientific research database uploaded by ISI cybersecurity officers once a week. In the encrypted section of the internal computer system lay the secret to Operation Scimitar—scientists knew that while Clostridium perfringens produced a dangerous bacterial toxin in its own right—more deadly than the Clostridium botulinum and tetani, and a hundred times more lethal than the Clostridium septicum toxin—that wasn’t the end of the story for this vicious bug. Working off stolen North Korean clinical papers from the 1960s, the Doctor had reassembled the experimentation on perfringens that had been abandoned decades ago, and identified where those earlier scientists had faltered. The North Koreans had isolated the most virulent strain—the epsilon toxin, or ETX—which, when injected into or fed to a goat or sheep, would kill the animal within one to three hours. Liver, kidney, heart, lungs and brain—as well as the central nervous systems—would collapse with a rolling thunder of oedema, lesions, loss of blood–brain barrier and cellular damage. It meant massive internal bleeding and the breakdown of bodily functions, and an agonising, thrashing death characterised by diarrhoea. There was no vaccine for ETX and no antibiotics strong enough to arrest it. If a strong enough dose was administered to a human, the victim would be dead inside three hours.

As soon as ETX had been isolated, and Western intelligence learned of its development, it immediately went onto the banned bioweapons list because of its specific danger to humans. Human-only cell lines such as G-402, HRTEC and ACHN were highly susceptible to the epsilon toxin and it was classified as a Category B Biological Agent by the United States Centers for Disease Control and Prevention and also by the French government. But the original researchers, while impressed with the potential of ETX for a widespread biological attack, became—in the Doctor’s opinion—sidetracked on a quest to deliver it effectively. Those scientists had tried to deliver it via aerosol or bomb, but had faced the ever-increasing need to concentrate and potentise the epsilon toxin in order to make it effective over large areas and populations, an expensive and resource-consuming task if it was going to be properly weaponised.