"Naysay. More than one Mantis, I think."

"The Mantis is a whole cla.s.s of mechs?"

"It's like dividing up water. Can't keep the lines drawn."

Toby felt a sense of comfort in the simple way his father talked, at the ,sound of his voice. "Dad, I--"

I "Son, I need you." Killeen said it exactly as he had said it before, same posture and tone. "I don't know how much more I can tell you. Just ...

let's try."

"Yeasay." Toby felt an immense relief. "Yeasay."

"I know how hard it's been. Look, you can have Shibo. I was--"

"Dad, I..." Toby stood mute. It was strange, speaking to a recording and wanting to force more out of it. But he had to tell the truth. "I had to pull Shibo."

The Killeen was startled. It shimmied in the air for a moment, as if this news shook the entire representation. "You... don't have the tools."

"I know. Did the best I could."

"She... was too much?"

"I couldn't manage her."

The Killeen nodded somberly. "She wasn't easy in the flesh, either"

"I think I got--"

Beside Killeen, condensing out of the air, was Shibo. She was translu- 287.

cent and her legs were gone but the upper body moved naturally. Headturning, first to Killeen, then to Toby. A thin smile."I... am still.., partially.., in ... here..."Walmsley said to Toby, "The reader is picking up flinging fields fromyou. She must be integrated into your perceptors."Toby nodded. "Yeasay, and wants to talk."Shibo's face pleaded. Her words sounded faintly in Toby's sensorium.

"I will be here.., to help. I had to come out. My dear... Killeen..."With small jerky movements and a wrenched face she turned to the Killeen. Toby felt an eerie current between the two. Valences moved, blunt and blind. They peered at each other a long time in silent, still air. Toby sensed a stuttering, hesitant sensation pa.s.s between them. Small signals across a furious gulf.Then Shibo lifted one hand, as if in salute--and vanished. Toby did not understand any of it.The Killeen shook his head and turned to look off into the distance.

His face seemed carved with deep, dry ravines."Good then," Walmsley said crisply. "You've sucked most of the juice out, I gather. Hurry along--we have work to do."When Toby looked' back to see his father's reaction, the Killeen was gone.The suddenness of loss staggered him. He dosed his eyes, steadied himself.Walmsley waved him on. "I know all this is a bit quick, but there really is pressing business."Toby took a last look at the endlessly roiling perspectives and followed Walmsley down the ramp. Into a dark under where light sharpened into hard points like a waiting bucket of stars.So time had done its work and his father had changed. So had Toby.

Who had been right or wrong was nothing now, a dry rattle among fading facts, lost in the curve of events. The places where the esty had scarred him were firmer and he could take whatever came without clinging to the past or foreboding for the future. His steps were light and he went forward into whatever would be.

Afterword.

To the best of my ability I have kept the imaginings of this novel, and those that came before in this series of novels, within the constraints set by astronomical observations. The explosion of our knowledge has been one of the wonders of the last few decades, but it's been tough on fiction writers.In the last decade the Very Large Array and other new varieties of "telescopes" have opened windows on our galactic center, with astonishing results. I've had to change my own ideas, and indeed, some of the inventions in this novel arise from theory as well--particularly, advances in the theory of gravitation.Plainly something enormously powerful is going on at the galactic center, apparently driven by a vast explosion about a million years ago.

Electrodynamic effects are strikingly strong within a few hundred light-years of the exact dynamical center, about which the entire spiral disk spins.

There, the magnetic field is at least a hundred times more intense than is typical in such mild-mannered neighborhoods of the galaxy as our own.

Apparently the long, luminous strands there derive from this strong field.

This suggests in turn that in the far more energetic active galactic nuclei of distant galaxies, magnetic fields may play a shaping role.The theoretical research I have done on the central region, wearing my hat as a professor of physics, takes this as the starting point. Similarly, in my fictions I have a.s.sumed this as given. It has been an unusual experience to conjure up imaginary events about a place that I was also doing hard calculations about. Freed of the bonds of The Astrophysical Journal, I have felt at liberty to speculate on what processes might have transpired, over the galaxy's ten billion years of furious cooking, to create forms of life and intelligence beyond our ken. (Coincidences: Just after writing the above paragraph, I got a note from the editor of that same august journal appreciating an earlier novel. Someday I must attempt to trace the interactions between science and science fiction. Or, better, an energetic graduate student. There's a good doctoral thesis lurking there ... )This novel and all those earlier in the "galactic" series--In the Ocean of Night, Across the Sea of Suns, Great Sky River, Tides of Light--owe a debt to 290.the scientists, editors, academics, and writers who have kept me going over two decades with ideas, advice, encouragement, and insightful reading.

These include, in no particular order, Marvin Minsky, Sheila Finch, David Hartwell, Mark Martin, David Brin, Betsy Mitch.e.l.l, David Samuelson, Steven Harris, Lou Aronica, Joe Miller, Jennifer Hershey, Stephen Hawking, Gary Wolfe, Norman Spinrad, David Kolb, Ruth Curl, and Arthur C. Clarke. Stimulating ideas kept drawing me on.

I especially thank Mark Morris, of UCLA, who a.s.sembled and directed the International Astronomical Union's Symposium on the Center of the Galaxy. The data and theories of that and later meetings spurred me to look beyond the models I had concocted for magnetic phenomena at the galactic center. Speaking at length about my own notions, and having them raked over by the observers--always a daunting prospect for a theorist!--made me confront the bewildering profusion of neon-brilliant displays, violent explosions, piercing energies, and (mysteriously) highly organized structures that mark our galactic center. Doing so opened my imagination to the possibilities of life (and, I suppose, of death) in so virulently extreme a place.

I apologize to the readers who have waited several years between volumes of this series. Other novels begged to be written.

And then there is Real Life, too, always demanding. My ideas about life in the universe have changed greatly since I set Nigel Walmsley on his odyssey in 1970 (beginning with a short story, "Icarus Descending," which was later slightly adapted and now opens In the Ocean of Night). Despite such evolutions, I have tried to keep these novels consistent. Events spanning several tens of thousands of years are not often reconciled, especially when the author has been off doing other things.

The concluding volume of this series is now in sight. I promise to have done and published within a year of this book's appearance. I may venture back into this universe in future, if the impulse occurs, but the plot and lines of reasoning should be intact and resolved by the end of the next novel. What a long, strange trip it's been.GREGORY BENFORD June1993