owed. "Did you think I
wasn't watching you every second out of the corner of my eye? I've been
ready to kill you from the moment your eyelids first fluttered!"

Mute, his face still livid with hate, Mark staggered to his feet.

"Come on!" Vance challenged. "If you think you can jump me before I pull
the trigger, come ahead! I'll be glad to take my chances before a jury
when you're dead!"

Elaine's fiance glared helplessly. His fists clenched and relaxed again
and again.

"You win," he said at last, his face grey beneath its tan. "Go on. Get
out. You've got us licked."

But the antiquarian shook his head.

"Not quite yet," he answered. "I've still got one job to do."

Then, so fast the eye could hardly follow, his gun-hand came up.

_Bang--bang--bang!_

* * * * *

Three shots he fired. Three shots, straight toward the easel in the
corner. Dead center into the mirror that stood upon it.

There was a wild tinkling of falling glass. The tablecloth slipped away.
Revealed the shattered remnants of the time mirror.

"I'm taking no chances!" cried Vance. "Professor Duchard's reputation as
a research physicist is too high." And then, mockingly: "However, I
doubt that even he can make any good use of that mirror now!"

With that final sally, he backed away and out the door, the Magnum in
his hand still grim and unwavering as he covered Mark and the old
scientist.

Curtly:

"I wouldn't come out too soon if I were you."

The door slammed shut.

Mark started forward. But the professor caught his arm.

"It is useless," the savant said. "To follow him would bring death and
would avail nothing, my boy. He has won."

Like men in a daze, then, they stared into each other's eyes. They saw
only dull hopelessness. The last spark was gone out.

Slowly, Mark walked over to the corner where stood the shattered mirror.
Looked blankly down at its fragments. Bending, he picked up a splinter.
Inspected it idly.

The next instant he whirled about.

"Professor Duchard!" he rapped. "How did this devil's looking-glass
work?"

The scientist looked up dispiritedly, shrugged.

"I could not make you understand. It is a complicated matter of
space-time theory--"

The other strode back to him. Gripped his shoulder.

"I don't care about the details. Just try to give me a simplified
version of the principle."

Professor Duchard gazed into the younger man's eyes. Caught the fierce
light within