The Ring was the most massive single structure in the Universe. It was like a boulder dropped into a pool: across a region hundreds of millions of light years wide its monstrous gravity well drew in galaxies as effortlessly as a lamp attracts moths. Now Paul was crossing the lip of that well, with the shining ruins of the Universe sliding alongside him. Eventually he saw how the fragile structures -- the filaments, loops and voids of galaxies which had emerged from the singularity itself -- were distorted, smashed, broken by the fall into this great flaw in space.

The galaxies -- all around the sky -- were tinged blue, he realized now. Blue shift.

He had come, at last, to the place all the galaxies were falling into.

The Ring was a hoop woven from a billion-light-year length of cosmic string. Paul's principal awareness focus was somewhere above the plane of the Ring. The near side of the artifact formed a tangled, impenetrable fence, twisted exuberantly into arcs and cusps, with shards of galaxy images glittering through the morass of spacetime defects. And the far side of the object was visible as a pale, hard band, remote across the blue-shifted sky.

Paul could study the Ring as Jim Bolder never had. With relish he sent sub-personalities skating along the tangled quantum functions that reached deep into the Ring's stretched spacetime.

Cosmic strings were residual traces of the ultrahigh, symmetric vacuum of the primordial epoch -- an era in which the forces of physics had yet to "freeze out" of a unified superforce -- and the strings were now embedded in the "empty space" of the Universe, like residual lines of liquid water in solid ice. And the strings were superconducting; as they moved through the primordial magnetic fields, huge currents -- of a hundred billion billion amps or more -- were induced in the strings...

The strings writhed, like slow, interconnected snakes, across space. The strings were moving at close to lightspeed. They left behind them flat, glowing wakes -- planes towards which matter was attracted, at several miles a second.

Paul looked into the center of the Ring. There he found a singularity. It was hoop-shaped, a circular flaw in space: a rip, caused by the rotation of the immense mass of the Ring. The singularity was about three hundred light years across -- much smaller than the diameter of the Ring itself.

If the Ring were spinning more slowly, the Kerr metric would be quite well-behaved. The singularity would be cloaked in two event horizons -- one-way membranes into the center -- and, beyond them, by an ergosphere: a region in which gravitational drag would be so strong that nothing sublight could resist its current.

But the Ring was spinning... and too rapidly to permit the formation of an event horizon, or an ergosphere. And so, the singularity was naked.