Gage had found her opportunity.

She summoned Maris Mackenzie. A pale Virtual of Mackenzie's disembodied head floated over an image of the hole and its companion.

The hole raised tides of light in the giant. Material snaked out of the giant in a huge, unlikely vortex which marched around the giant's equator. The vortex fueled an accretion disc around the hole, a glowing plane of rubble that spanned more than Earth's orbit around its Sun.

Some of the giant's matter fell directly into the hole. The infall was providing the hole with angular momentum -- making it spin faster. Because of the infall the hole was rotating unusually fast, thirty times a second.

"Hear me out," Gage said.

"Go on," said Maris Mackenzie.

"If a black hole isn't spinning -- and it's uncharged -- then it has a spherical event horizon."

"Right. That's the Schwarzschild solution to Einstein's equations. Spherically symmetric--"

"But if you spin the hole, things get more complicated." It was called the Kerr-Newman solution. "The event horizon retreats in, a little way. And outside the event horizon there is another region, called the ergosphere."

The ergosphere cloaked the event horizon. It touched the spherical horizon at its poles, but bulged out at the equator, forming a flattened spheroid.

"The greater the spin, the wider the ergosphere," Gage said. "The hole ahead is four miles across. It's spinning so fast that the depth of the ergosphere at the equator is a hundred and forty yards."

Mackenzie looked thoughtful. "So?"

"We can't enter the event horizon. But we could enter the ergosphere, or clip it, and get away safely."

"Um. Inside the ergosphere we would be constrained to rotate with the hole."

"That's the plan. I want to flyby, clipping the ergosphere, and slingshot off the black hole."

Mackenzie whistled. Pixels fluttered across her face, as she devoted processing power to checking out Gage's proposal. "It could be done," she said eventually. "But we would have a margin of error measured in yards. It would require damn fine piloting."

"I'm a damn fine pilot. And we can take a lot of stress, remember." It's not as if we have to protect anyone living.

"Why do you want to do this?"

"Because," Gage said, "the missile will follow me through the ergosphere. But after we've passed through, the hole will have been changed. The missile won't be able to work out how..."

"We'll have to get consent to this from the others. The eighty--"

"Come on," Gage said. "Most of them have retreated into their own Virtual heads. There's hardly anybody out here, still thinking, save you and me."

Slowly, Mackenzie smiled.

For Gage's scheme to work, the speed of Chiron would have to be raised much higher. When Chiron flew by the hole it would need an angular momentum comparable to that of the hole itself. So the drones ravaged Mackenzie's frozen ocean, hurling the stuff of Chiron into the GUTdrives.

Chiron approached the lightspeed limit asymptotically.