Ambassador Nitworth glowered across his mirror-polished, nine-foot platinum desk at his assembled staff.

"Gentlemen, are any of you familiar with a race known as the Qornt?"

There was a moment of profound silence. Nitworth leaned forward, looking solemn.

"They were a warlike race known in this sector back in Concordiat times, perhaps two hundred years ago. They vanished as suddenly as they had appeared. There was no record of where they went." He paused for effect.

"They have now reappeared—occupying the inner planet of this system!"

"But, sir," Second Secretary Magnan offered. "That's uninhabited Terrestrial territory...."

"Indeed, Mr. Magnan?" Nitworth smiled icily. "It appears the Qornt do not share that opinion." He plucked a heavy parchment from a folder before him, harrumphed and read aloud:

His Supreme Excellency The Qorn, Regent of Qornt, Over-Lord of the Galactic Destiny, Greets the Terrestrials and, with reference to the presence in mandated territory of Terrestrial squatters, has the honor to advise that he will require the use of his outer world on the thirtieth day. Then will the Qornt come with steel and fire. Receive, Terrestrials, renewed assurances of my awareness of your existence, and let Those who dare gird for the contest.

"Frankly, I wouldn't call it conciliatory," Magnan said.

Nitworth tapped the paper with a finger.

"We have been served, gentlemen, with nothing less than an Ultimatum!"

"Well, we'll soon straighten these fellows out—" the Military Attache began.

"There happens to be more to this piece of truculence than appears on the surface," the Ambassador cut in. He paused, waiting for interested frowns to settle into place.

"Note, gentlemen, that these invaders have appeared on terrestrial controlled soil—and without so much as a flicker from the instruments of the Navigational Monitor Service!"

The Military Attache blinked. "That's absurd," he said flatly. Nitworth slapped the table.

"We're up against something new, gentlemen! I've considered every hypothesis from cloaks of invisibility to time travel! The fact is—the Qornt fleets are indetectible!"

The Military Attache pulled at his lower lip. "In that case, we can't try conclusions with these fellows until we have an indetectible drive of our own. I recommend a crash project. In the meantime—"

"I'll have my boys start ............