He turned to Benson. "You can rely on his dates and happenings; his
interpretation's strictly capitalist, of course," he said.

Black-jacket shook his head. "You first, Gregory," he said. "Tell him
how he got here, and then I'll tell him why."

"I believe," Gregory began, "that in your period, fiction writers made
some use of the subject of time-travel. It was not, however, given
serious consideration, largely because of certain alleged paradoxes
involved, and because of an elementalistic and objectifying attitude
toward the whole subject of time. I won't go into the mathematics and
symbolic logic involved, but we have disposed of the objections; more,
we have succeeded in constructing a time-machine, if you want to call it
that. We prefer to call it a temporal-spatial displacement field
generator."

"It's really very simple," the woman called Paula interrupted. "If the
universe is expanding, time is a widening spiral; if contracting, a
diminishing spiral; if static, a uniform spiral. The possibility of
pulsation was our only worry...."

"That's no worry," Gregory reproved her. "I showed you that the rate was
too slow to have an effect on...."

"Oh, nonsense; you can measure something which exists within a
microsecond, but where is the instrument to measure a temporal pulsation
that may require years...? You haven't come to that yet."

"Be quiet, both of you!" the man with the black coat and the white bands
commanded. "While you argue about vanities, thousands are being