Professor Firebrenner had explained it carefully. "Time-perception depends on the structure of the Universe. When the Universe is expanding, we experience time as going forward; when it is contracting, we experience it going backward. If we could somehow force the Universe to be in stasis, neither expanding nor contracting, time would stand still."

"But you can't put the Universe in stasis," said Mr. Atkins, fascinated.

"I can put a little portion of the Universe in stasis, however. " said the professor. " Just enough to hold a ship. Time will stand still and we can move forward or backward at will and the entire trip will last less than an instant. But all the parts of the Universe will move while we stand still, while we are nailed to the fabric of the Universe. The Earth moves about the Sun, the Sun moves about the core of the Galaxy, the Galaxy moves about some center of gravity, all the Galaxies move.

"I calculated those motions and I find that 27.5 million years in the future, a red dwarf star will occupy the position our Sun does now. If we go 27.5 million years into the future, in less than an instant that red dwarf star will be near our spaceship and we can come home after studying it a bit."

Atkins said, "Can that be done?"

"I've sent experimental animals through time, but I can't make them automatically return. If you and I go, we can then manipulate the controls so that we can return."

"And you want me along?"

"Of course. There should be two. Two people would be more easily believed than one alone. Come, it will be an incredible adventure."

Atkins inspected the ship. It was a 2217 Glenn-fusion model and looked beautiful. "Suppose," he said, "that it lands inside the red dwarf star."

"It won't," said the professor, "but if it does, that's the chance we take."

"But when we get back, the Sun and Earth will have moved on. We'll be in space."

"Of course, but how far can the Sun and Earth move in the few hours it will take us to observe the star? With this ship we will catch up to our beloved planet. Are you ready, Mr. Atkins?"

"Ready," sighed Atkins.

Professor Firebrenner made the necessary adjustments and nailed the ship to the fabric of the

Universe while 27.5 million years passed. And then, in less than a flash, time began to move forward again in the usual way, and everything in the Universe moved forward with it.

Through the viewing port of their ship, Professor Firebrenner and Mr. Atkins could see the small orb of the red dwarf star.

The professor smiled. "You and I, Atkins," he said, "are the first ever to see, close at hand, any star other than our own Sun."

They remained two-and-a-half hours during which they photographed the star and its spectrum and as many neighboring stars as they could, made special coronagraphic observations, tested the chemical composition of the interstellar gas, and then Professor Firebrenner said, rather reluctantly, "I think we had better go home now."

Again, the controls were adjusted and the ship was nailed to the fabric of the Universe. They went 27.5 million years into the past, and in less than a flash, they were back where they started.

Space was black. There was nothing.

Atkins said, "What happened? Where are the Earth and Sun?"

The professor frowned. He said, " Going back in time must be different. The entire Universe must have moved."

"Where could it move?"

"I don't know. Other objects shift position within the Universe, but the Universe as a whole must move in an upper-dimensional direction. We are here in the absolute vacuum, in primeval Chaos."

"But we're here. It's not primeval Chaos anymore."

"Exactly. That means we've introduced an instability at this place where we exist, and that means -"

Even as he said that, a Big Bang obliterated them. A new Universe came into being and began to expand.