Already the mysterious powers had struck. Departments of State had been entered and important papers abstracted. The _Germania_ had mysteriously disappeared in mid-Atlantic, and a shipping panic had ensued. There were tales of mysterious figures materializing out of nothingness. It was known that the conspirators were in possession of certain chemical and electrical devices with which they hoped to achieve their ends. The Superintendent of the penitentiary had had in his pocket an authorization to stop the execution of Von Kettler after he stood on the trap. Dead, he would be a mere mark of vengeance: alive, he might be persuaded to furnish some clue to the headquarters of the miscreants. * * * * * And behind the conspirators loomed the unknown figure that signed itself the Invisible Emperor--in the communications that poured in to the White House and to the rulers of other nations. In the threats that were materializing with stunning swiftness. Who was he? Rumor said that a former European ruler had not died as was supposed: that a coffin weighted with lead had been buried, and that he himself in his old age, had gone forth to a mad scheme of world conquest with a body of his nobles. It had been practically a state of war since the shipment of gold, guarded by a detachment of police, had been stolen in broad daylight outside Baltimore, the police clubbed and killed by invisible assailants--as they claimed. The press was under censorship, troops under arms, and it was reported that the fleet was mobilizing. In the midst of it all, Washington shopped, danced, feasted, flirted, like a swarm of may flies over a treacherous stream. Intelligence was alert. As Dick started to drive away from the Slovakian Embassy, a man stepped quickly to the side of the car and thrust an envelope into his hand. Dick opened it quickly. He was wanted by Colonel Stopford at once, not at the camouflaged Headquarters at the War Department, but at the real Headquarters where no papers were kept but weighty decisions were made. And to that devious course the Government had already been driven. Dick parked his car in a side street--it would have been under espionage in any of the official parking places--and set off at a smart walk toward his destination. Nobody would have guessed, from the appearance of the streets, that a national calamity was impending. The shopping crowds were swarming along the sidewalks, cars tailed each other through the streets; only a detachment of soldiers on the White House lawn lent a touch of the martial to the scene. * * * * *