“Is a dense star cluster. And as such, it has no definite boundaries. That’s what I meant by saying we are already in it. In the thin verge at least.” Laure pointed to the diffuse, jeweled magnificence that was rising higher above these wastes in the wake of the red and blue suns. “Yonder’s the main body, and Kirkasant is somewhere there. But this system here is associated. I’ve checked proper motions and I know.”

“I could have accepted some such picture while on Serieve,” Hirn said. “But Vandange was so insistent that a star cluster like this cannot be.” Laure visualized the sneer behind his faceplate. “I thought that he, belonging to the master civilization, would know whereof he spoke.”

“He does. He’s merely rather unimaginative,” Laure said. “You see, what we have here is a globular cluster. That’s a group made up of stars close together in a roughly spherical volume of space. I’d guess you have a quarter million, packed into a couple of hundred light-years’ diameter.

“But globular clusters haven’t been known like this one. The ones we do know lie mostly well off the galactic plane. The space within them is much clearer than in the spiral arms, almost a perfect vacuum. The individual members are red. Any normal stars of greater than minimal mass have gone off the main sequence long ago. The survivors are metal-poor. That’s another sign of extreme age. Heavy elements are formed in stellar cores, you know, and spewed back into space. So it’s the younger suns, coalescing out of the enriched interstellar medium, that contain a lot of metal. All in all, everything points to the globular clusters being relics of an embryo stage in the galaxy’s life.

“Yours, however—! Dust and gas so thick that not even a giant can be seen across many parsecs. Plenty of mainsequence stars, including blues which cannot be more than a few million years old, they burn out so fast. Spectra, not to mention planets your explorers visited, showing atomic abundances far skewed toward the high end of the periodic table. A background radiation too powerful for a man like me to dare take up permanent residence in your country.

“Such a cluster shouldn’t be!”

“But it is,” Graydal said.

Laure made bold to squeeze her hand, though little of that could pass through the gauntlets. “I’m glad,” he answered.

“How do you explain the phenomenon?” Hirn asked. “Oh, that’s obvious…now that I’ve seen the things and gathered some information on its path,” Laure said. “An improbable situation, maybe unique, but not impossible. This cluster happens to have an extremely eccentric orbit around the galactic center of mass,. Once or twice a gigayear, it passes through the vast thick clouds that surround that region. By gravitation, it sweeps up immense quantities of stuff. Meanwhile, I suppose, perturbation causes some of its senior members to drift off. You might say it’s periodically rejuvenated.

“At present, it’s on its way out again. Hasn’t quite left our spiral arm. It passed near the galactic, midpoint just a short while back, cosmically speaking; I’d estimate less than fifty million years. The infall is still turbulent, still condensing out into new stars like that blue giant shining on us. Your home sun and its planets must be a product of an earlier sweep. But there’ve been twenty or thirty such since the galaxy formed, and each one of them was responsible for several generations of giant stars. So Kirkasant has a lot more heavy elements than the normal planet, even though it’s not much younger than Earth. Do you follow me?”