"Well, they are--cars, you might say, with wheels that go into the
body when you take off. They can do, oh, 5,000 miles an hour in the
ionosphere, 50 miles up."
"Fifty miles," Maitland mused. "Then they're sealed tight, so the air
doesn't leak out?" Ingrid nodded. "How do they work? Rocket drive?"
"No." She plucked at her lower lip. "I do not understand it very well.
You could picture something that hooks into a gravity field, and pulls.
A long way from the Earth if would not work very well, because the
field is so thin there.... I guess I just cannot explain it very well
to you."
"That's all I need." Maitland licked his lips and frowned. "On that
point, anyway. Another thing--Swarts told me I'd be here for about a
week. Is there any set procedure involved in that? Have other persons
been brought to this period from the past?"
She laughed. "Thousands. Swarts has published nearly a hundred case
studies himself, and spent time adding up to years in the 19th and 20th
centuries."
Maitland interrupted incredulously. "How on Earth could he ever manage
to keep that many disappearances quiet? Some of those people would be
bound to talk."
She shook her head definitely. "The technique was designed to avoid
just that. There is a method of 'fading' the memories people have of
their stay here. The episode is always accepted as a period of amnesia,
in the absence of a better explanation."
"Still, in thousands of cases...."
"Spread out over centuries in a total population of billions."