“Shut up, Mark,” Louise said mildly. “Now, Spinner. Listen carefully. You have three waldoes — three boxes. We believe — we think — the one directly in front of you is interfaced to the hyperdrive control, and the two to your sides connect to the intraSystem drive.”

“IntraSystem?”

“Sublight propulsion, to let you travel around the Solar System. All right? Now, Spinner, today we aren’t going to touch the hyperdrive — in fact, that waldo is disabled. We just want to see what we can make of the intraSystem drive. All right?”

“Yes.” Spinner looked at the two boxes; the touch-pad lights glowed steadily, in reassuring colors of yellow and green.

“On your left hand waldo you’ll see a yellow pad. It should be illuminated. See it?”

“Yes.”

Louise hesitated. “Spinner, try to be ready. We don’t know what to expect. There might be changes…”

“I’m ready.”

“Touch the yellow pad — once, and as briefly as you can…”

Spinner tried to put aside her fear. She lifted her hand -

Spinner-of-Rope. Don’t be afraid.

Startled, she twisted in her couch.

It had been a dry, weary voice — a man’s voice, sounding from somewhere inside her helmet.

Of course, she was alone in the cage.

It’s just a machine, the voice said now. There’s nothing to fear…

She thought, Lethe. What now? Am I going crazy?

But, strangely, the voice — the sense of some invisible presence, here in the cage with her — was somehow comforting.

Spinner held her right hand over the waldo. She pressed her gloved finger to the yellow light.

A subtle change in the light, around her. There was no noise, no sense of motion.

She glanced down, through the bars of her cage.

The ice was gone. Callisto had vanished.

She twisted in her seat, the straps chafing against her chest, and peered out of her cage. The rings of Jupiter and the Sun’s swollen form covered the sky unperturbed by the disappearance of a mere moon. She couldn’t see the Northern.

She spotted a ball of ice, small enough to cover with her fist, off to her right, below the nightfighter.

Could that be Callisto? If so, she’d traveled thousands of miles from the moon, in less than a heartbeat — and felt nothing.

She looked behind her.

The Xeelee nightfighter had spread its sycamore-seed wings. From within their hundred-yard shells, sheets of nightdarkness — hundreds of miles long — curled across space behind her, occluding the stars.

At her touch, the ancient Xeelee craft had come to life.

She screamed and buried her faceplate in her gloves.

Lieserl soared out from the core, out through the shell of fusing hydrogen, and inspected her maser convection loops. She sensed the distorted echoes of her last set of messages, as they had survived their cycles through the coherence paths of the convection loops.

She adjusted the information content of her maser links, and initiated new messages. She added in the latest information she’d gleaned, and restated — in as strong and simple a language as she could muster — her warnings about the likely future evolution of the Sun.

When she was done, she felt something within her relax. Once more she’d scratched this itch to communicate; once more she’d assuaged her absurd, ancient feelings of guilt…

But it was only after she’d sent her communication that she studied, properly, the cycled remnants of her last signals.

She allowed the maser bursts to play over her again. The messages had changed — and this time it wasn’t simple degradation. How was this possible? Some unknown physical process at the surface of the red giant, perhaps? Or — she speculated, her excitement growing as she began to see traces of structure within the changes — or was there someone outside: someone still alive, and recognizably human — and trying to talk to her?

Feverishly she devoured the thin information stream contained in the maser bursts.

Fifty thousand miles from Callisto, pods from the Northern hung in a rough sphere. At the center of the sphere, the magnificent wings of the Xeelee ship remained unfurled, darkly shimmering — almost alive.

Spinner sat with Louise within the safe, enclosing glass walls of a pod. Louise, with a touch on the little control console before her, guided the pod around the Xeelee nightfighter; neighboring pods slid across space, bubbles of light and warmth. The wings were immense sculptures in space, black on black. Spinner could hear Mark whispering in Louise’s ear, and numbers and schematics rolled across a data slate on Louise’s lap.

Spinner’s faceplate dangled at her back, and she relished the feel of fresh air against her face. It was wonderful simply not to breathe in her own stale exhalations.

She’d dug her father’s arrow-head out of her suit so that it dangled at her chest; she fingered it, rubbing her hands compulsively over its smooth lines.

Louise glanced at Spinner. “Are you all right now?” She sounded apologetic. “Mark got to you as quickly as he could. And — ”

Spinner-of-Rope nodded, curtly. “I wasn’t hurt.”

“No.” Louise glanced down at her slate again; her attention was clearly on the data streaming in about the activated nightfighter. She murmured, “No, you did fine.”

“Yeah,” Spinner grunted. “Well, I hope it was worth it.”

Louise looked up from her slate. “It was. Believe me, Spinner; even if it might be hard for you to see how. The very fact that you weren’t harmed, physically, by that little jaunt has told us volumes.”

Now Mark’s voice sounded in the air. “You traveled tens of thousands of miles in a fraction of a second, Spinner. You should have been creamed against the bars of that cage. Instead, something protected you…”

Louise looked at Spinner. “He has a way of putting things, doesn’t he?”

They laughed together. Spinner felt a little of the numbness chip away from her.

“Mark’s right,” Louise said. “Thanks to you, we’re learning at a fantastic rate about the nightfighter. We know we can use it without killing ourselves, for a start… And, Spinner, understanding is the key to turning anything from a threat into an opportunity.”

Louise took the pod on a wide arc around the unfurled wings of the Xeelee craft. The wings were like a star-free hole cut out of space, beneath Spinner-of-Rope; they retained the general sycamore-seed shape of the construction-material framework, but were vastly extended. Spinner could see ’bots toiling patiently across the wings’ surface.

“This far out, the mass-energy of the wing system is actually attracting the pod, gravitationally,” Louise murmured. “The wings have the mass equivalent of a small asteroid… I can see from my slate that the pod’s systems are having to correct for the wings’ perturbation.

“Let’s go in a little way.”

She took the pod on a low, sweeping curve over the lip of one wing and down toward its surface. The wing, a hundred miles across, was spread out beneath Spinner like the skin of some dark world; the little pod skimmed steadily over the black landscape.

Louise kept talking. “The wing is thin — as far as we can tell its thickness is just a Planck length, the shortest distance possible. It has an extremely high surface tension — or, equivalently, a high surface energy density — so high, in fact, that its gravitational field is inherently non-Newtonian; it’s actually relativistic… Is this making any sense to you, Spinner?”

Spinner said nothing.

Louise said, “Look: from a long way away, the pod was attracted to the wings, just as if they were composed of normal matter. But they’re not. And, this close, I can detect the difference.”