"What?" Lvov tried to focus.

"The wormhole instability, when we crashed. It did cause an Alcubierre wave."

"What's an Alcubierre wave?"

"The Interface's negative energy region expanded from the tetrahedron, just for a moment. The negative energy distorted a chunk of space time. The chunk containing the flitter, and us."

On one side of the flitter, Cobh said, space-time had contracted. Like a model black hole. On the other side, it expanded -- like a re-run of the Big Bang, the expansion at the beginning of the Universe.

"An Alcubierre wave is a front in space-time. The Interface -- with us embedded inside -- was carried along. We were pushed away from the expanding region, and towards the contraction."

"Like a surfer, on a wave."

"Right." Cobh sounded excited. "The effect's been known to theory, almost since the formulation of relativity. But I don't think anyone's observed it before."

"How lucky for us," Lvov said drily. "You said we traveled faster than light. But that's impossible."

"You can't move faster than light within space-time. Wormholes are one way of getting around this; in a wormhole you are passing through a branch in space-time. The Alcubierre effect is another way. The superluminal velocity comes from the distortion of space itself; we were carried along within distorting space.

"So we weren't breaking lightspeed within our raft of space-time. But that space-time itself was distorting at more than light-speed."

"It sounds like cheating."

"So sue me. Or look up the math."

"Couldn't we use your Alcubierre effect to drive starships?"

"No. The instabilities and the energy drain are forbidding."

One of the snowflake patterns lay mostly undamaged, within Lvov's reach. She crouched and peered at it. The flake was perhaps a foot across. Internal structure was visible within the clear ice as layers of tubes and compartments; it was highly symmetrical, and very complex. She said to Cobh, "This is an impressive crystallization effect. If that's what it is." Gingerly she reached out with thumb and forefinger, and snapped a short tube off the rim of the flake. She laid the sample on her desk. After a few seconds the analysis presented. "It's mostly water-ice, with some contaminants," she told Cobh. "But in a novel molecular form. Denser than normal ice, a kind of glass. Water would freeze like this under high pressures -- several thousand atmospheres."

"Perhaps it's material from the interior, brought out by the chthonic mixing in that region."

"Perhaps." Lvov felt more confident now; she was intrigued. "Cobh, there's a larger specimen a few feet further away."

"Take it easy, Lvov."

She stepped forward. "I'll be fine. I--"

The surface shattered.

Lvov's left foot dropped forward, into a shallow hole; something crackled under the sole of her boot. Threads of ice crystals, oddly woven together, spun up and tracked precise parabolae around her leg.

The fall seemed to take an age; the ice tipped up towards her like an opening door. She put her hands out. She couldn't stop the fall, but she was able to cushion herself, and she kept her face plate away from the ice. She finished up on her backside; she felt the chill of Pluto ice through the suit material over her buttocks and calves.