“Do you ever wonder why they gave us that sense?” Orphu had asked when Mahnmut described the vegetation scent as they entered the broad Valles Marineris Estuary from the Tethys.

“What’s that?” said Mahnmut.

“Smell.”

The Europan moravec had to think about that. He’d always taken his sense of smell for granted, although it was useless underwater or on the surface of Europa, and all but useless in The Dark Lady ’s environmental crèche—in other words, everywhere he’d existed. “I could smell toxic fumes in the sub or in the pressurized cubbies of Conamara Chaos Central,” he said at last, knowing that this wasn’t a satisfactory answer. Moravecs had better built-in alarms for such dangers.

Orphu rumbled softly. “I might have smelled the sulfur when I was on Io’s surface, but who would want to?”

“You can smell things?” said Mahnmut. “That doesn’t make much sense for a hardvac moravec.”

“Indeed,” said Orphu. “Nor does the fact that I spend . . . spent . . . a majority of my time viewing things on the human’s visible-light spectrum, but I did whenever possible.”

Mahnmut thought about this as well. It was true; he did the same, even though he could easily see deep into the infrared and UV reaches of the spectrum. Orphu’s vision, Mahnmut knew, incorporated visualizations of radio frequencies and magnetic field lines, neither common to old-style humans, which made a lot more sense for a moravec working in the hard radiation fields of Galilean space. So why did the Ionian choose the limited human “visible” wavelengths most frequently?

“I think it’s because our designers and all the subsequent generations of moravecs secretly wanted to be human,” said Orphu, answering Mahnmut’s unstated question with no accompanying rumble of irony or amusement. “The Pinocchio Effect, as it were.”

Mahnmut didn’t agree with that, but he felt too depressed to argue the point.

“What do you smell now?” asked Orphu.

“Rotting vegetation,” said Mahnmut as the felucca took the far southern channel into the broad estuary. “It smells like Shakespeare’s Thames at low tide.”

On the first week of sailing upriver, to keep from going mad from the inactivity, Mahnmut disassembled and inspected—as best he could—the three other pieces of recovered cargo, Orphu being the fourth.

The smallest artifact, a smooth ovoid not much larger than Mahnmut’s compact torso, was the Device—the single most important element in the late Koros III’s mission. All Mahnmut and Orphu knew about the Device was that the Ganymedan was supposed to deliver it to Olympus Mons, and, under proper circumstances not shared with Mahnmut or Orphu, activate it.

Mahnmut probed the Device with sonar and removed a tiny part of its reflective transalloy shell. Its function was not revealed. The actual machine, if machine it was, was macromolecular—essentially a single nano-squared machined molecule with a chewy central core of tremendous energy contained only by the macromolecule’s internal fields. The only “device-device” that Mahnmut could find associated with the shell was a current-generated zipper initiator. Thirty-two volts applied to just the right place on the shell would . . . do something . . . to the macromolecule inside.

“It could be a bomb,” said Mahnmut as he carefully replaced the square centimeter of metal shell.

“Quite a bomb,” muttered Orphu. “If the em-molecule is mostly a binding eggshell, we’re talking a planet-buster here. The yolk would be on us.”

Pretending he hadn’t heard the pun in order to preserve their friendship and to keep from having to throw Orphu over the railing, Mahnmut had looked out at the passing canyon walls—they were still sailing within three kilometers of the high southern cliffs bordering the broad inland sea that day—and imagined all that red-rocked, terraced and striated beauty gone. He thought of the periscoping mangroves that grew in the Martian lower estuary marshlands, the natural topiary-gorse visible on the valley cliffs’ higher walls, even the fragile blue sky with ripples of high cirrus above the rock—and tried to imagine it all destroyed by one quantum explosion huge enough to rip a world apart. It hardly seemed right.

“Can you think of anything else it could be other than a bomb?” he asked Orphu.

“Not offhand,” said the Ionian. “But something containing that much pent-up implosive quantum energy represents technology way beyond my understanding. I’d suggest you treat the Device gently, put some cushions under it or something, but since it’s already survived the chariot people’s attack and atmospheric entry that fried me and killed your ship, it can’t be too delicate. Give it a kick in the ass and move on. What’s the next piece of cargo?”

The next piece of cargo was just a bit larger than the Device, but much more understandable. “It’s some sort of squirt communicator,” said Mahnmut. “It’s all folded in on itself, but I can see that if I activate it, it’ll unfurl onto its own tripod, aim a large dish toward the sky, and fire a serious burst of . . . something. Encoded energy in tightband or k-maser or perhaps even modulated gravity.”

“Why would Koros have needed that?” asked Orphu. “The comsats are still in orbit and the spaceship could have relayed any sort of tightbeam or radio back to Galilean space. Hell, even your sub could have contacted home.”

“Maybe this wasn’t meant to broadcast to Jupiter space,” suggested Mahnmut.

“Where then?”

Mahnmut had no suggestions.

“How was Koros going to code the message?” asked the Ionian.

“There are virtual jackports,” said Mahnmut after inspecting the compact machinery carefully under its nanocarbon skin. “We could download everything we’ve seen and learned, encrypt it, and activate it. Unless it needs an activation code or something. Want me to jack in and check?”

“No,” said Orphu. “Not yet.”

“I’ll close it then.”

“What does this communicator use for a squirt power source?” asked Orphu before Mahnmut could close up the device.

Mahnmut wasn’t familiar with the technology, but he described the magnetic container and forcefield schematics.

“My, my,” said Orphu. “That’s Chevkovian felschenmass. Artificial antimatter of the kind the Consortium used to fuel the first interstellar probe. There’s enough energy there to keep us alive and kicking for another several earth centuries if there were a way for us to tap into it.”

Mahnmut had felt his organic heart skip a beat. “Could we have used it to replace the fusion reactor on the Lady?”

Orphu was quiet for several long seconds. “No, I don’t think so,” he said at last. “Too much energy released too fast and too hard to tame. It’s possible that you and I could tap into its trickle field, but I don’t think we could have powered up The Dark Lady with it even if the sub could have been repaired. And you said you couldn’t do the repairs alone, right?”

“It would have taken the Conamara Chaos ice docks,” said Mahnmut, feeling a strange combination of regret and relief at the news that this wasn’t a fix for the poor Lady. As much as the death of his ship depressed him, the thought of turning back and sailing the 2,000-plus kilometers back to it was even more depressing.

The last piece of cargo was the largest, the heaviest, and the hardest for Mahnmut to figure out.

The container was a bamboo-three cube a meter and a half tall by two meters wide, wrapped in clear transpolymer. A brief inspection showed Mahnmut that the cube was filled with hundreds of square meters of micro-thin polyethylene stealth-composite with high-performance solarcell-strips embedded in the fabric, 24 interconnected, partially nested, articulated conical titanium segments, four pressurized canisters containing what his sensors said was helium, an oxygen-nitrogen mix, and methanol, 8 atmospheric pulse thrusters with jack-in controllers, and, finally, 12 fifteen-meter folded buckycarbon cables attached to the four sides of the bamboo-three box the thing came in.