David Brin - Existence

“… replaced in these green cells by another gas.” Tor completed the thought, while nodding. “I think we’ve found the missing hydrogen, people.”

For emphasis, she reached out toward one of the nearby green cells. The “safe” ones that were there to protect life and property, making disaster impossible.

It all made sense, now. Smart polymers were programmable-all the way down to the permeability of any patch of these gas-containing cells, the same technology that made seawater desalinization cheap and ended the Water Wars. But it was technology, and so could be used in a multitude of ways. If you were very clever, you might insert a timed instruction where two gas cells touched, commanding one cell to leak into another. Create a daisy chain. Vent helium into the sky. Transfer gas from hydrogen cells into neighboring helium cells to maintain pressure, so that no one noticed. Then trigger automatic systems to crack onboard water and “replace” that hydrogen, replenishing the main cells. Allow the company to assume a slow leak into the sky is responsible. Continue.

Continue until you have replaced the helium in enough of the green cells to turn the Spirit into a flying bomb.

“The process must be almost complete by now,” she murmured, peering ahead toward the great zep port, where dozens of mighty dirigibles could already be seen, some of them vastly larger than this passenger liner, bobbing gently at their moorings. Spindly fly-cranes went swooping back and forth as they plucked shipping containers from ocean freighters at the nearby Potomac Docks, gracefully transferring the air-gel crates to waiting cargo-zeppelins for the journey cross continent. A deceptively graceful, swaying dance that propelled the engines of commerce.

The passenger terminal-dwarfed by comparison to those giants-seemed to beckon with a promise of safety. But indicators showed that it still lay ten minutes away.

“We have issued a clamor, Tor,” assured the voice in her head. “Every channel. Every agency.”

A glance at spec-telltales showed Tor that, indeed, the group mind was doing its best. Shouting alarm toward every official protective service, from Defense to Homeworld Security. Individual members were lapel-grabbing friends and acquaintances, while smart-mob attendance levels climbed into five figures, and more. At this rate, surely the professionals would be taking heed. Any minute now.

“Too slow,” she said, watching the figures with a sinking heart. Each second that it took to get action from the Protector Caste, the perpetrators of this scheme would also grow aware that the jig is up. Their plan was discovered. And they would have a speedup option.

Speaking of the perps, Tor wondered aloud.

“What can they be hoping to accomplish?”

“We’re pondering that, Tor. Timing suggests that they aim to disrupt the Artifact Conference. Delegates arriving at the Naval Research Center are having a cocktail reception on the embankment right now, offering a fine view toward the zep port, across the river.

“Of course it is possible that the reffers plan to do more than just put on a show, while murdering three hundred passengers. We are checking to see if the Umberto tug has been meddled with. Perhaps the plan is to hop rails and collide with a large cargo-zep, before detonation. Such a fireball might rock the Capitol, and disrupt the port for months.

One problem with a smart-mob. The very same traits that multiplied intelligence could also make it seem dispassionate. Insensitive. Individual members surely felt anguish and concern over Tor’s plight. She might even access their messages, if she had time for commiseration.

But pragmatic help was preferable. She kept to the group mind level.

“ One (anonymous) member (a whistle-blower?) has suggested a bizarre plan using a flying-crane at the zep port to grab the Spirit of Chula Vista when it passes near. The crane would then hurl the Spirit across the river, to explode right at the Naval Research Center! In theory, it might just be possible to incinerate-”

“Enough!” Tor cut in. Almost a minute had passed since realization of danger and the issuance of a clamor. And so far, no one had offered anything like a practical suggestion.

“Don’t forget that I’m here, now. We have to do something.”

“Yes,” the voice replied, eagerly and without the usual hesitation. “There is sufficient probable cause to get a posse writ. Especially with your credibility scores. We can act, with you performing the hands-on role.

“Operational ideas follow:

“CUT THE TOWING CABLE.

(Emergency release in gondola. Reachable in four minutes.

Risk: possible interference from staff. Ineffective at saving the zeppelin/passengers.)

“PERSUADE ZEP COMPANY TO COMMENCE EMERGENCY VENTING PROCEDURES.

(Communication in progress. Response so far: obstinate refusal…)

“PERSUADE ONBOARD STAFF TO COMMENCE EMERGENCY VENTING PROCEDURES.

(Attempting communication despite company interference…)

“PERSUADE COMPANY TO ORDER PASSENGER EVACUATION.

(Communication in progress. Response so far: obstinate refusal…)

“UPGRADE CLAMOR. CONTACT PASSENGERS. URGE THEM TO EVACUATE.

(Risks: delay, disbelief, panic, injuries, fatalities, lawsuits…)”

The list of suggestions seemed to scroll on and on. Rank-ordered by plausibility-evaluation algorithms, slanted by urgency, and scored by likelihood of successful outcome. Individuals and subgroups within the smart-mob split apart to urge different options with frantic vehemence. Her specs flared, threatening overload.

“Oh, screw this,” Tor muttered, reaching up and tearing them off.

The real world-unfiltered. For all of its paucity of layering and data-supported detail, it had one special trait.

It’s where I am about to die, she thought.

Unless I do something fast.

At that moment, the zep crew attendant arrived. He rounded the final corner of a towering gas cell, coming into direct view-no longer a shadowy authority figure, warped and refracted by the tinted polymer membranes. Up close, it turned out to be a small man, middle-aged and clearly frightened by what his own specs had started telling him. All intention to arrest or detain Tor had evaporated before he made that turn. She could see this in his face, as clearly as if she had been monitoring vital signs.

WARREN, said a company nametag.

“Wha-what can I do to help?” he asked in a hoarse whisper.

Though hired for gracile weight and people skills, the fellow clearly possessed some courage. By now he knew what filled many of the slim, green-tinted membranes surrounding them both. And it didn’t take a genius to realize the zep company was unlikely to help, during the time they had left.

“Tool kit!” Tor held out her hand.

Warren fumbled at his waist pouch. Precious seconds passed as he unfolded a slim implement case. Tor found one promising item-a vibrocutter.

“Keyed to your biometrics?”

He nodded. Passengers weren’t allowed to bring anything aboard that might become a weapon. This cutter would respond to his personal touch and no other. It required not only a fingerprint, but volition-physiological signs of the owner’s will.

“You must do the cutting, then.”

“C-cutting…?”

Tor explained quickly.

“We’ve got to vent this ship. Empty the gas upward. That’ll happen to a main cell if it is ruptured anywhere along its length, right? Automatically?”

A shaky nod. She could tell Warren was getting online advice, perhaps from the zep company. More likely from the same smart-mob that she had called into being. She felt strong temptation to put her own specs back on-to link-in once more. But she resisted. Kibitzers would only slow her down right now.