Again he rang like a bell. His flesh buzzed like bronze, his hair stood on end. How things worked; it had to be; and he rang. He danced. He circled his occhialino like the Earth circling the sun, spinning in a slow four-step as he made his little orbit on the altana, arms swinging, fingers directing the music of the spheres, which despite Kepler’s craziness seemed suddenly plausible. Indeed an audible chord was now ringing silently in his ears.

Then came a knock on the door below. He halted his dance with a jerk, looked down the staircase on the outside of the house.

Cartophilus was there inside the gate, holding a shuttered lantern, looking up at him. Galileo rushed down the stairs and raised a fist as if to strike him. “What is this?” he exclaimed in a low furious voice. “Is he here again?”

Cartophilus nodded. “He’s here.”

CHAPTER FIVE

The Other

When she saw that it was not that I would not speak, but that, dumbstruck, I could not, she gently laid her hand on my breast and said, “It is nothing serious, only a touch of amnesia, the common disease of deluded minds. He has forgotten for a while who he is, but he will soon remember once he has recognized me. To make it easier for him I will wipe a little of the blinding cloud of the world from his eyes.”

—BOETHIUS, The Consolation of Philosophy

GALILEO STRODE TO THE GATE and hauled it open just as another knock pounded it. The tall stranger stood there looking down at him, his massive perspicillum’s case in a heap at his feet. He looked flushed, and his eyes were like black fire.

Galileo felt his blood pound in his head. “Already you have found me.”

“Yes,” the man said.

“Did this servant you foisted on me tell you where I was?” Galileo demanded, jerking a thumb toward the hangdog Cartophilus.

“I knew where you were. Are you willing to make another night journey?”

Galileo’s mouth was dry. He struggled to remember more than that flicker of blue. Blue people—”Yes,” he said, before knowing he would.

The stranger nodded dourly and glanced over at Cartophilus, who trudged out the gate and hauled the case over the paving stones into the courtyard. Jupiter lay low in the sky above Scorpio, still tangled with the trees.

The man’s heavy perspicillum seemed more than a spyglass. Galileo helped Cartophilus set up the tripod and to lift the fat tube, which looked to be made of something like pewter, but felt heavier than gold. When they had the device set on its stand and pointed toward Jupiter, which aiming it seemed to do on its own, Galileo swallowed hard, feeling again his dry mouth, his nameless apprehension. He sat on his stool, looked into the strangely luminous glass of the eyepiece. He fell up into it.

Around him lofted a transparent glow, like talcum in sunlight. What is it, he tried to say, and must have succeeded; the stranger replied in his crow’s Latin. “Around Jupiter hums a magnetic field so strong that people would die of it, if unprotected. It has to be held off by a similar field of our own creation—a counterforce. The glow marks an interference of the two forces.”

“I see,” Galileo murmured.

So he stood on the surface of Europa—again. Some memory of his previous visit had come back to him, though vaguely. The stars trembled overhead as if he were still looking at them through his occhialino, the bigger ones fulgurous, shedding flakes and threads of light into the blackness around them.

The surface of Europa, on the other hand, was exceptionally sharp and clear. The flat ice extended to the horizon that circled them so tightly, opaque white tinted the color of Jupiter, and stained blue or ochre in some areas. Sometimes it was pocked or chewed at the surface, sometimes deeply cracked in radial patterns. Elsewhere it was smooth as glass. Everywhere it was littered with small rocks, and here and there stood a few house-sized boulders, pitted with holes and depressions. Most of the rocks were almost as black as the sky, but a few were metallic gray, or the red of the red spot low on the banded immense surface of Jupiter. That awesome globe loomed directly overhead, huge in the starry night sky even though only half lit. That was the thing that was twenty-five or thirty times bigger, which he had been trying to remember. Its dark half was very dark.

Possibly the tight horizon and the thin air gave the landscape its unreal clarity. The thin air was cool, the sun nowhere to be seen. The two men cast sharp shadows on the ice under them. Galileo, constantly troubled at home by fogged or ringed vision, stared around avidly. Here everyone had hawks’ eyes.

“This is a hot spot, in local terms,” the stranger said in the breathy silence. To Galileo the ice looked everywhere the same, and cold. Their feet crunched as the stranger led him to one of the biggest boulders.

There proved to be a door in this rock, which was not a rock, but rather some kind of carriage or ship, roughly ovoid in shape, lying on the ice like a great black egg. Its surface was smooth, not rocky or metallic, but more like horn or ebony.

A door in this surface opened by sliding sideways in the wall, revealing a small vestibule or antechamber at the top of low black steps. The stranger gestured to Galileo, indicating the entry.

“This is our vessel. We have heard that the Europans are going to stage an illegal incursion into the ocean under this ice. They have ignored our warnings, and the relevant authorities in the Jovian system have declined to interfere, so we are taking it on ourselves to stop them. We think any incursion will be potentially disastrous in ways these people haven’t even considered. We want to intercept them if we can, and keep them from doing harm. And at the very least, see what they do down there. If what happens is as bad as I fear it could be, they will not tell the truth about it. So we must follow them in. With luck we will get down there first, and can stop them when they break through the layer of ice into the water below.”

“And you want me along?” Galileo asked.

“Yes.” Ganymede hesitated, then said, “If you do happen to get exposed to certain experiences, it might be a help to you later on.”

Then something caught his attention over Galileo’s shoulder, and he looked startled; Galileo turned and saw a silver object on a tripod, like the perspicillum only bigger, coming down on a pillar of white fire, roaring faintly in the thin air.

The tall man put a hand to Galileo’s shoulder. “If there is danger, I will transport you back to your own time. The transition may be abrupt.”

A slit in the silver craft opened and a figure in white emerged.

“Do you know who this is?” Galileo asked.

“Yes, I think so. You met her before, when we spoke to the council.”

“Ah yes. Hera, she said. Jupiter’s wife?”

“She thinks she’s that big,” the stranger said sourly, then added under his breath, “It’s almost true.”

The woman was indeed large: tall, broad-shouldered, wide-hipped, thick-armed, deep-chested. She approached and stopped before them, looking down at the stranger with her ironic smile. “Ganymede, I know you hate what they plan to do here,” she said. “And yet here you are. What’s going on? Are you planning to hurt them?”

The stranger, who did not look like Galileo’s idea of Ganymede, faced her like an upright ax. “You know what they’ll say about this on Callisto if they hear about it. We hold the same view they do. The only difference is that we’re willing to do something about it.”