He gave the old man an OK sign. Next to him stood Commissioner Jane. Geoff was glad she'd made it up for this.

Ouroboros blotted out the sun. The tugs strained; the positioning rockets blasted; the giant rock crept down. Radio chatter died. Geoff watched, frightened and exhilarated. He couldn't help but think of Carl. Far off in the distance, at the horizon, Ouroboros and 25 Phocaea touched, and a clamor of voices swelled in his headset. The ground underfoot shook. The tug pilots had done it again, with their uncanny precision.

Geoff revved his engine and with Amaya, Kam, and Ian, led the bikers toward the base of the ramps.

This wasn't the best ice harvest ever. That would never be true again, without Carl here to watch with him. But an ice shipment this big, coming now? It would surely do. He led the way up the bucking and twisting ramp, accelerated, and soared into the Big Empty amid rising ice and stone ejecta-followed by a hundred rocketbikers and their nets and the renewed hopes of his people.

ACKNOWLEDGMENTS.

I owe a debt of grat.i.tude to many who helped me improve this book.

THE CONSULTANTS. Several people shared their time, advice, and expertise. For help with astrophysics and computing, thanks go to Chris Crawford, Steven Gould, Jerry Weinberg, and Rusty Allen. Dr. Gwen Lattimore helped me get the medical details right, and helped me with key elements of the miniature technology. David Porterfield gave me a.s.sistance with the business and technology of mining (and let me fire his Several people shared their time, advice, and expertise. For help with astrophysics and computing, thanks go to Chris Crawford, Steven Gould, Jerry Weinberg, and Rusty Allen. Dr. Gwen Lattimore helped me get the medical details right, and helped me with key elements of the miniature technology. David Porterfield gave me a.s.sistance with the business and technology of mining (and let me fire his awesome spud launcher! awesome spud launcher!). Nalo Hopkinson, Melinda Snodgra.s.s, and Walter Jon Williams gave me good tips on Upsider society and life.

THE CRITIQUERS. Those who read portions of this as a work-in-progress gave me the incisive, high-rez feedback I needed to pummel the story into shape: Holly Deuel Gilster, Steven Gould, Jane Lindskold, George R. R. Martin, and Pati Nagle, along with all the wise and thoughtful members of PlotBusters and Critical Ma.s.s. Those who read portions of this as a work-in-progress gave me the incisive, high-rez feedback I needed to pummel the story into shape: Holly Deuel Gilster, Steven Gould, Jane Lindskold, George R. R. Martin, and Pati Nagle, along with all the wise and thoughtful members of PlotBusters and Critical Ma.s.s.

SAFE HAVEN. A two-week spring writing retreat in Tucson saw me through a sticky patch. Ellen Kushner, Delia Sherman, and Terri Windling made an exquisite, private desert setting available to me, and Emma Bull and Will Shetterly were stalwart hosts and marvelous dinner companions. A two-week spring writing retreat in Tucson saw me through a sticky patch. Ellen Kushner, Delia Sherman, and Terri Windling made an exquisite, private desert setting available to me, and Emma Bull and Will Shetterly were stalwart hosts and marvelous dinner companions.

HERE A NOD, THERE A NOD. Chris Crawford's Solvesol-interface concept was the basis of my Tonal_Z, Cory Doctorow's Chris Crawford's Solvesol-interface concept was the basis of my Tonal_Z, Cory Doctorow's whuffie whuffie strongly influenced my sammies, and Bruce Sterling let me hijack the Viridians for my own nefarious ends. strongly influenced my sammies, and Bruce Sterling let me hijack the Viridians for my own nefarious ends.

LAST BUT NOT LEAST. I owe deep thanks to my editor, Patrick Nielsen Hayden, and to my agent, Matt Bialer. Your steady belief in me helped me keep faith with myself. I owe deep thanks to my editor, Patrick Nielsen Hayden, and to my agent, Matt Bialer. Your steady belief in me helped me keep faith with myself.

These people all supported me in my aims, but in the end it was I who decided what to put in and what to leave out. Any infelicities, sins, or errors you encounter belong to me alone.