Below him fled a broadly flat, curdled surface, glowing white, a pool of gas that rotated visibly, churning like storm clouds on Earth. This was all that was left of the mass of stars and planets and living things that had been unlucky enough to fall into this lethal pit. He knew that a black hole destroyed all information about the matter it took into its event horizon, everything but spin, mass, and charge; but whatever the turbulent plasma below had once been, it was already reduced to nothing but fodder for the endlessly voracious Chandra.

He had long passed the closest approach achieved by his older self, Pirius Blue, on his scouting jaunt. Nobody in human history had ever approached the event horizon of a supermassive black hole so closely—and he had to go in a lot closer yet.

Nothing he saw was real, of course. All he saw was a Virtual rendering, reconstructed in wavelengths he was comfortable with, the glare turned down; if he had looked out of his blister he would have been blinded in an instant. But he thought he could sense the churning of this dish of plasma the size of a solar system, perhaps even the gut-wrenching gravities of the event horizon itself. He could feel the vast astrophysical processes around him. He was a mote trapped inside an immense machine.

“One minute to closest approach to the horizon,” Bilson warned.

Pirius felt his heart beat faster, but he tried to keep his voice light. “Remember your training. We practiced on rocks a couple of hundred kilometers across. Today we’re hitting a target a hundred million klicks wide. It ought to be easy.”

“But,” Cabel said dryly, “it’s a hundred million klicks of black-hole event horizon.”

“Shut up,” said Bilson, the fear sharp in his voice.

“No flak,” Cabel said. “They still haven’t seen us. We might actually live through this.”

“Thirty seconds,” the navigator called.

“Stand ready.”

And suddenly it was ahead of him, the center of everything, a sphere of glowing gas like a malevolent sun rising from the curdled accretion disc. The event horizon itself was invisible, of course: dark on dark, it was a surface from which not even light could escape. The glow he saw was the final desperate emission of infalling matter.

Under the control of its CTC processor, the ship rose up from the plane of the disc.

Pirius looked down as the accretion disc fell away. At the disc’s inner edge the infalling matter, having been spun and churned and compressed in its final frantic orbits, at last reached the event horizon. Wisps and tendrils, gaudy and pathetic, snaked in from that inner edge, glowing ever more feverishly.

He looked ahead into the ball of churning gas that surrounded the event horizon. The horizon was a sphere, but vast, a sphere as wide as Mercury’s orbit. The greenship’s path should take it skimming up toward its pole, kissing the surface tangentially at the point of closest approach, a precise one hundred kilometers from the mathematically defined surface of the event horizon itself.