th a frown of concentration on his face. And his
quick eyes caught at once a thing another person might have overlooked
for quite a while.

The wheel was dish-shaped, as all roulette wheels are. In its rounded
bottom were numbered slots, where the little ivory ball was to end its
journey and proclaim gambler's luck.

But the little ball was not in one of the bottom slots!

The tiny ivory sphere was half up the rounded side of the wheel, like a
pea clinging alone high up on the slant of a dish!

An exclamation came from Keane's lips. He stared at the ball. What in
heaven's name kept it from rolling down the steep slant and into the
rounded bottom? Why would a sphere stay on a slant? It was as if a bowl
of water had been tilted--and the water's surface had taken and retained
the tilt of the vessel it was in instead of remaining level!

He lifted the ball from the sloping side of the wheel. It came away
freely, but with an almost intangible resistance, as if an unseen rubber
band held it. When he released it, it went back to the slope. He rolled
it down to the bottom of the wheel. Released, it rolled back up to its
former position, like water running up-hill.

Keane felt a chill touch him. The laws of physics broken! A ball
clinging to a slant instead of rolling down it! What dark secret of
nature had Doctor Satan mastered now?

But the query was not entirely unanswered in his mind. Already he was
getting a vague hint of it. And a little later the hint was broadened.

The phone rang. He answered it.

"Mr. Keane? This is Doctor Grays. The autopsy on Wilson has been begun,
and already a queer thing has been disclosed. It's about his heart."

"Yes," said Keane, gripping the phone.

"His heart is ruptured in a hundred places--as though a little bomb had
exploded in it! Don't ask me why, because I can't even give a theory.
It's unique in medical history."

"I won't ask you why," Keane said slowly. "I think--in a little
while--I'll tell you why."

He hung up and strode toward the door. But at the roulette table he
paused and stared at the wheel with his gray eyes icily blazing.

_It seemed to him the wheel had moved a little!_

He had unconsciously lined up the weirdly clinging ball with the knob on
the outer door, as he examined it awhile ago. Now, as he stood in the
same place, the ball was not quite in that line. As if the wheel had
rotated a fraction of an inch!

"Yes, I think that's it," he whispered, wit