olding out. After a moment's
hesitation he took it, instructed Barney to wait, and closed the door
firmly.

Listening to Fredericks' footsteps receding into the house, Barney lit
a cigarette, and was pleased to find that his hands were as steady as
if he had been on the most ordinary of calls. The envelope contained
two sets of photographs, dated and indicating the time of day. The
date was the same for both sets; the recorded time showed the pictures
had been taken within fifteen minutes of one another. The central
subject in each case was Dr. McAllen, sometimes accompanied by
Fredericks. One set of photographs had been obtained on Mallorca, the
other in Sweetwater Beach at McAllen's house.

Barring rocket assists, the two old men had been documented as the
fastest moving human beings in all history.

Several minutes passed before Fredericks reappeared. With a face which
was now completely without expression, he invited Barney to enter, and
conducted him to McAllen's study. The scientist had the photographs
spread out on a desk before him. He gestured at them.

"Just what--if anything--is this supposed to mean, sir?" he demanded
in an unsteady voice.

Barney hesitated aware that Fredericks had remained in the hall just
beyond the study. But Fredericks obviously was in McAllen's
confidence. His eavesdropping could do no harm.

"It means this, doctor--" Barney began, amiably enough; and he
proceeded to tell McAllen precisely what the photographs meant.
McAllen broke in protestingly two or three times, then let Barney
conclude his account of the steps he had taken to verify his
farfetched hunch on the pier without further comment. After a few
minutes Barney heard Fredericks' steps moving away, and then a door
closing softly somewhere, and he shifted his position a trifle so that
his right side was now toward the hall door. The little revolver was
in the right-hand coat pocket. Even then Barney had no real concern
that McAllen or Fredericks would attempt to resort to violence, but
when people are acutely disturbed--and McAllen at least was--almost
anything can happen.

* * * * *

When Barney finished, McAllen stared down at the photographs again,
shook his head, and looked over at Barney.

[Illustration]

"If you don't mind," he said, blinking behind his glasses, "I should
like to think about this for a minute or two."

"Of course, doctor," Barney said politely. McAllen settled