y Roberts herself told you, nothing can exist before it
exists. Neither can anything exist after it is out of existence. If
you returned with a Dynapack, for example, it would revert to a lump
of various metals, because that was what it was in your period. But
let me give you a more personal instance. Do you remember coming back
from your first trip with dust on your hand?"

"Yes. I must have fallen."

"On one hand? No, Mr. Weldon. May Roberts was greatly upset by the
incident; she was afraid you would realize why the hamburger had
turned to dust--and why the old people died of starvation. _All_ of
them, not just a few."

He paused, giving me a chance to understand what he had just said. I
did, with a sick shock.

"If I ate your food," I said shakily, "I'd feel satisfied until I was
returned to my own time. _But the food wouldn't go along with me!_"

* * * * *

Blundell nodded gravely. "And so you, too, would die of malnutrition.
The foods we have given you existed in your era. We were very careful
of that, so careful that many of them probably were stored years
before you left your time. We regret that they are not very palatable,
but at least we are positive they will go back with you. You will be
as healthy when you arrive in the past as when you left.

"Incidentally, she made you change your clothes for the same
reason--they had been made in 1930. She had clothing from every era
she wanted visited and chose old people who would fit them best.
Otherwise, you see, they'd have arrived naked."

I began to shake as if I were as old as I'd pretended to be on the
stage. "She's going to pull me back! If I don't bring her the
information about the Dynapack, she'll shoot me!"

"That, Mr. Weldon, is our problem," Blundell said, putting his hand
comfortingly on my arm to calm me.

"Your problem? I'm the one who'll get shot, not you!"

"But we know in complete detail what will happen when you are returned
to the 20th Century."

I pulled my arm away and grabbed his. "You know that? Tell me!"

"I'm sorry, Mr. Weldon. If we tell you what you did, you might think
of some alternate action, and there is no knowing what the result
would be."

"But I didn't get shot or die of malnutrition?"

"That much we can tell you. Neither."

They all stood up, so bright and attractive in their colorful clothes
that I felt like a shirt-sleeved stage hand who'd wandered in on a
costume play.

"You