Amid the twin crises of World War I and the deadly Spanish Flu pandemic, Mycroft Holmes faces an unprecedented threat: not from enemy lines, but from within 10 Downing Street itself. When rumours surface of lavish parties hosted by Prime Minister Lloyd George, Mycroft must deploy every tool of manipulation—blackmail, investigative diversion, and calculated silence—to prevent a scandal that could topple the government. As Sherlock Holmes and Dr Watson are drawn into a web of deception, the line between duty and decadence blurs in a tale of power, pestilence, and the price of statecraft.