Egg and its ever-present glare was gone.

Most of the sky was black and starless. In the distance was a small elliptical patch with a few dozen stars in it. The stars in the patch of sky were blue to ultraviolet in color. What was most confusing was that the patch of starlight seem to be rotating, while he and the rest of the tanks were standing still.

"That was a Kerr s.p.a.ce-warp!" Pierre said out loud.

"That is correct," came a voice. The image of Sky-Speaker was on the screen.

"That can't be!" said Pierre. "I remember from my gravitational engineering courses that a Kerr ring with the ma.s.s of a sun would have a one-kilometer hole. The compensator asteroid ma.s.ses are orders of magnitude less ma.s.sive than the sun. The biggest ring they could make would be less than a micron in diameter. According to Einstein, that was impossible. ..."

"Einstein was intelligent, but human," said Sky-Speaker. "He failed to combine gravity and electromagnetism. We have. The unified theory agrees with Einstein for large ma.s.ses. For very small ma.s.ses, the diameters of magnetized s.p.a.ce-warps are larger than Einstein predicted."

While Sky-Speaker was talking, Pierre noticed that the string of free-floating spheres was being moved.

The tanks with their clouds of robot-tended equipment had moved back under the rotating patch of sky.

The cheela robots formed the tanks into a circle and accelerated them until they were mov- ing in the same direction as the whirling patch of sky above them. The acceleration continued.

"We're moving in time," said Pierre.

"Yes," said Sky-Speaker. "The rate is one month normal galactic time per ten minutes proper time for your crew. You will return through s.p.a.ce-warp in one hour. Six months will have pa.s.sed in normal s.p.a.ce. The asteroid Oscar will have returned."

The cheela robots now had communication links set up between all the tanks, and Pierre could see each of the remaining crew members on one of his miniature screens.

"Is everyone okay?" he asked.

"Yes," said Abdul. "But I'm not looking forward to going back through that meat grinder again."

"The engineering check program indicates a problem," said Jean.

"I'm surprised it is still functional after the drastic changes the cheela made," said Seiko.

"What's the problem?" Pierre asked.

"There is a leak in Tank 6," Jean replied.

"Whose tank is that?" asked Pierre.

"Mine," replied Abdul. "She's right. I've lost some pressure. The water must have frozen and plugged the leak, though. The pressure seems to have stabilized."

"The tank must be repaired!" Cesar said. "It surely cannot withstand another trip through those extreme tidal forces."

"The cheela can work miracles. But I don't think they can weld the mist we call steel. I'll just have to risk it." Abdul paused, looking puzzled, then turned away from the video pickup and put his hands against the back wall of the tank.

"Hey!" he said. "I feel little tiny tugs of gravity near the wall. They keep zipping back and forth."

"I can see some activity outside your tank," Seiko told him. "It looks like an electric arc. I think they are attempting to weld the leak shut."

"I hope it holds," said Abdul.

05:06 CREW TIMEWEDNESDAY 22 JUNE2050.

(00:01 GMT SUNDAY 25 DECEMBER 2050).

"Ten seconds to reentry," said Sky-Speaker. Pierre saw the view outside his porthole tilt and shift as the circle of tanks turned into a line of tanks that swooped away from the patch of sky in a large arc, then dove headfirst through the Kerr-warp at high speed. The next few milliseconds pa.s.sed too quickly for the tortured humans to follow.

As Oscar neared the s.p.a.ce-warp the five tanks popped, one by one, out of the flat circle of black. After the pa.s.sage of the second tank, the diameter of the ring expanded a little, then shrank just as the third tank pa.s.sed through. The oscillations in the ring grew larger, and the fourth tank was highly distorted by the tides of the contracting ring. The cheela obviously hadn't expected this instability. They managed to slow the last tank down so that it wasn't trying to get through the ring at its minimum radius, but it wasn't enough. The tank ruptured, spewing a human being and gobbets of water into the vacuum of s.p.a.ce.

The cheela robots a.s.sembled the remaining four tanks in a line just below the periapsis of the plunging asteroid, Oscar. The asteroid pa.s.sed rapidly over the tanks, and one at a time its gravity field jerked the tanks upward in a high trajectory that took them quickly away from the tides of Egg.

The cheela attempted to help the remaining human. They moved a piece of tank to shield him from the radiation from Egg. They kept him from being torn apart by the gravity tides by making a miniature compensator ring of dense s.p.a.cecraft that circled around him. However, they couldn't prevent him from being dragged back toward the ma.s.sive s.p.a.ce-warp. His eyes temporarily protected from the vacuum of s.p.a.ce by his underwater mask, Abdul looked up and waved goodbye to his departing comrades. Then, pushing off from the heavy piece of steel tank, he dove headfirst into the whirling black ring to join the atoms that had once been Amalita. Just before he reached the ring his body was momentarily surrounded by a swirling cloud of white-hot specks. There was a flash and he was gone.

05:15 CREW TIME WEDNESDAY 22 JUNE 2050.

(00:10 GMT SUNDAY 25 DECEMBER 2050).

The four tanks were met at the top of their trajectory by a flitter from St. George that took them in tow.

While one s.p.a.cesuited figure secured the tow line, another came over and peered in Pierre's porthole. It was Commander Carole Swenson. He saw a big grin on her face as she put her helmet against the outer wall of the tank and hollered a greeting.

"That's the last time I let you have a s.p.a.ceship to drive," she said. "Did you get the license number of the truck?"

She knew Pierre couldn't talk underwater except through his throat mike, so she shouted one more message and pushed back to the flitter for the ride in.

"I've got a surprise for you," she said. "See you in the air lock."

Pierre couldn't understand why Carole was so happy. Perhaps it was because at least four of the crew of Dragon Slayer made it back. All Pierre could think of, however, was that two of them didn't. They had been his responsibility, and now they were dead. He dreaded what he had to do next. He would have to let their families know. How do you tell someone that their loved ones had been torn to atoms?

05:50 CREW TIME WEDNESDAY 22 JUNE 2050.

(00:45 GMT SUNDAY 25 DECEMBER 2050).

The four tanks were crowded into the cargo air lock on St. George, and soon the lock was full of b.a.l.l.s of water and sloppy, wet, sobbing people.

"I'm sorry about Amalita and Abdul, Carole," Pierre said as he took off his mask. "If only there was something I could...."

"Hush...." Carole was smiling happily. "Come! I want you to meet a couple of friends of ours." She grabbed his hand and pulled him down the corridor to the communications room. The room was empty except for the communications operator. Pierre was completely baffled.

"h.e.l.lo, Pierre." It was Amalita's voice.

"Did you have a nice ride up from Egg?" Abdul's voice asked.

Pierre whirled around to face a communications screen at one end of the room. He saw video images of Amalita and Abdul in two segments of the screen.

"Surprise! Surprise!" Abdul yelled.

"Itreally is us," Amalita said. "Or at least all of us that counts."

"I even have a moustache to twirl." Abdul lifted his hand to twirl the end of his long moustache. "And it feels like the real thing even though it's made of software instead of hardware."

Carole squeezed Pierre's arm in rea.s.surance as she spoke. "The cheela scanned them thoroughly just before their bodies were destroyed," she said. "Their intellect patterns now reside in cheela supercomputers."

"But Amalita was irradiated and frozen," Pierre protested.

"I admit I have a lot of missing memories," said Amalita. "But the basic personality is still there."

"Yeah!" said Abdul. "She's just as bossy as ever."

"Hush!"

"See?" said Abdul, raising his eyebrows and shrugging his shoulders. "She'll be even more bossy when we get into those walk-around bodies they're building for us."

"We have slowed ourselves down so we can say goodbye to all of you and our families," said Amalita.

"Then we had better get back up to normal cheela rates if we are going to stay up with what is going on down here...."

"Doc! Seiko! Jean!" Abdul called. "Over here on the screen."

Pierre turned around to see astonished looks on the remainder of his crew as they came into the communications room. His chronometer chimed the hour, and he looked down at it. He started to reset it to make it agree with the clock on the wall, but decided against it. Not many people lived on a time-line six months shorter than the rest of the universe.

06:00 CREW TIME WEDNESDAY 22 JUNE 2050.

The long day was over.

Technical Appendix

The following sections are selected extracts from the book,My Visit With Our Nucleonic Friends, by Pierre Caraot Niven, Ballantine Interplanetary, New York, Earth and Washington, Mars (2053). This is the only book to win the n.o.bel, Pulitzer, Hugo, Nebula, and Moebius prizes in the same year (2053).

DRAGON'S EGG.

The home star of the cheela was given the picturesque name Dragon's Egg by the humans because it is a star right-at the end of the constellation Draco (the Dragon), as if the Dragon had left an egg behind in its nest. The cheela coincidently also called their home Egg because it is the source of lifegiving heat and light, and glows warmly like the eggs they lay.

Egg, like most neutron stars, rotates rapidly because it is a small, compact body and only 20 kilometers in diameter that condensed from a large, slowly rotating red giant star many millions of kilometers across.

Most of the ma.s.s, magnetic field, and angular momentum of the original star ended up in the neutron star.

Dragon's Egg has a surface gravity of 67 billion Earth gravities, a magnetic field at the poles of a trillion gauss, and a rotation rate of 5.0183495 revolutions per second. Thus, one turn of Egg is roughly one-millionth of an Earth day. This approximate million-to-one relative time scale also seems to apply to the cheela life processes. Our nucleonic friends think, talk, live, and die a million times faster than we humans.

RELATIVETIME SCALES.

The cheela use a base twelve numbering system since they have twelve eyes. The cheela units of time are given in the following table, along with the roughly equivalent time span for humans, taking into account the average lifetime of the cheela compared to the average lifetime of a human.

Human Time Cheela Time Remarks

1 day 3,000 g 100 cheela generations 1 hour 126 g 4 cheela generations 45 min 94 g cheela lifetime 15 min 31 g cheela generation 29 sec 1 g = 1 great = 144 turns (equiv. to human year) 0.2 sec 1 t = 1 turn of Egg (equiv. to human day) 17 msec 1/12t =dothturn (equiv. to human hour) 1.4 msec 1/144t = grethturn (equiv. to human 10 min) 115 msec 1/1728t = methturn (equiv. to human minute) 10 msec 1/20736t = sethturn (equiv. to human 4 sec) 800 nsec 1/28832t = blink (equiv. to human blink)

OUR NUCLEONIC FRIENDS.

One can hardly imagine a more alien life form than a cheela. A typical cheela weighs the same as a typical human, about 70 kilograms; but the nuclei in the cheela body have lost their electron clouds, so the nuclei are condensed into a tiny body that is squashed by the high gravity and stretched by the high magnetic field into an oval pancake shape a half-centimeter in diameter and a half-millimeter high-alittle larger than a sesame seed.

The body is tough and flexible, with a tread on the bottom like that of a slug. Unlike a slug, a cheela can move equally well in any direction. The cheela have twelve eyes s.p.a.ced around their periphery, giving them 360-degree vision. The eyes are up on stalks like those of a slug, but because of the high gravity the stalk is thicker. The cheela see using the ultraviolet and soft X-rays emitted by the 8200-K glowing surface of Egg.

Despite their alien appearance, the cheela are not thought of as ugly, terrifying monsters. Instead, they have become our friends. One suspects that their small size may have something to do with it, as well as the fact that they cannot use anything on Earth, or even the Earth itself. Anything made out of normal matter would collapse at a touch from their ultra-dense nucleonic bodies.

LIFE ON A NEUTRON STAR.