David Brin - Existence

“We passed the Beltway,” she murmured, a little surprised that the diligent guardians of Washington’s defensive grid allowed the Spirit to pass through that wall of sensors and rays without delay or scrutiny. Below and ahead, she could make out the great locomotive tug, Umberto Nobile, hauling hard at the tow cable, puffing along the Glebe Road Bypass. Fort Meyers stood to the left. The zeppelin’s shadow rippled over a vast garden of gravestones-Arlington National Cemetery.

“The powers-that-be have downgraded our rumor,” said the voice inside her ear. “The nation’s professional protectors are chasing down more plausible threats… none of which has been deemed likely enough to merit an alert. Malevolent zeps don’t even make it onto the Threat Chart.”

Tor clicked and flicked the attention-gaze of her specs, glancing through the journalist feeds at MediaCorp, which were now-belatedly-accessible to a reporter of her level. Seven minutes after the rise in tension caused by that spam of rumors, a consensus was already forming. The spam flood had not been intended to distract attention from a terror attack, concluded mass-wisdom. It was the attack. And not a very effective one, at that. National productivity had dropped by a brief diversion factor of one part in twenty-three thousand. Hardly enough damage to be worth risking prosecution or retaliation. But then, neohackers seldom cared about consequences.

Speaking of consequences; they were already pouring in from her little snooping expedition. The mavens of propriety at MediaCorp, for example, must be catching up on recent events. A work-related memorandum flashed in Tor’s agenda box, revising tomorrow’s schedule for her first day of employment at the Washington Bureau. During lunch-right after basic orientation-she was now required to attend counseling on the Exercising Good Judgment in Impromptu Field Situations.

“Oh great,” she muttered, noticing also that the zeppelin company had applied a five hundred dollar fine against her account for Unjustified Entry into Restricted Areas.

PLEASE REMAIN WHERE YOU ARE, MS. POVLOV,said an override message. AN ATTENDANT WILL ARRIVE AT YOUR POSITION SHORTLY IN ORDER TO HELP YOU RETURN TO YOUR SEAT FOR LANDING.

“Double great.”

Ahead, beyond the curve of the dirigible’s skin, she spotted the massive, squat bulk of the Pentagon, bristling with missiles, lenses, and antennae… still a highly-protected enclave, even ten years after the Department of Defense moved its headquarters to “an undisclosed location in Minnesota.”

Soon, the mooring towers and docking ports of Reagan-Clinton National Skydrome would appear, signaling the end of her cross-continental voyage. Also finished-despite a string of interesting stories, from the Atkins Center to Hamish Brookeman railing at the Godmakers’ Conference-was all chance of a blemish-free start to her new career in Big Time Media.

She addressed the group mind. “I don’t suppose any of you have bright ideas?”

But it had already started to unravel. Membership numbers were falling fast, like rats deserting a sinking ship. Or-more accurately-monkeys. Moving on to the next shiny thing.

“Sorry, Tor. People are distracted. They’ve been dropping out to watch the reopening of the Artifact Conference. You may even glimpse some limos arriving at the Naval Research Center, just across the Potomac. Take a look as the Spirit starts turning for final approach…”

Blasted fickle amateurs! Tor had made good use of smart-mobs in the past. But this time was likely to prove an embarrassment. None of them would have to pay fines or face disapproval in a new job.

“Still, a few of us remain worried,” the voice continued. “That rumor had something… I can’t put my finger on it.”

The “voice” was starting to sound individualized and had even used the first person “I.” A sure sign of low numbers. And yet, Tor drew some strength from the support. Before an attendant arrived to escort her below, there was still time for a little last-minute tenacity.

“Can I assume we still have some zep aficionados in attendance?”

“Hardly anyone else, Tor. Some us are fanatics.”

“Good, then let’s apply fanatical expertise. Think about that leakage we discussed a while ago. We’ve been assuming that this zeppelin is making hydrogen to make up for a significant seep, into the air outside. That’d be pretty harmless, I agree. Have any of those amateur scientists studied the air near Spirit ’s flight path, yet?”

A pause.

“Yes, several have reported in. They found no dangerous levels of hydrogen in the vicinity of the ship, or in its wake. The seep is probably dissipating so fast…”

“Please clarify. No dangerous levels? Is it possible they found no sign of a hydrogen leak at all ?”

The pause extended several seconds longer, this time. Suddenly the number of participants in the group stopped falling. In the corner of Tor’s specs, she saw membership levels start to rise again, slowly.

“Now that’s interesting,” throbbed the consensus voice in her ear.

“Several of those amateur scientists have joined us now.

“They report seeing no appreciable leakage. Zero extra hydrogen along the flight path. How did you know?”

“I didn’t. Call it a hunch.”

“But at the rate that Spirit has been replacing hydrogen…”

“There has to be some kind of leak. Right.” She finished that thought aloud. “Not into the baggage compartment or passageways, either. We’d have detected that. But the missing hydrogen must be going somewhere.”

Tor frowned. She could see a shadow moving beyond the grove of tall, cylindrical gas cells. A figure approaching. A crewman or attendant, coming to take her, firmly, gently, insistently, back to her seat. The shape wavered and warped as seen through the mostly transparent polymer tubes-slightly pinkish for hydrogen and then greenish tinted for helium.

Tor blinked. Suddenly feeling so dry mouthed that she could not speak aloud, only subvocalize.

“Okay… then… please ask the amscis to take some more spectral scans along the path of this zeppelin. Only this time… look for helium .”

The inner surface of her specs showed a flurry of indicators. Amateur scientific instruments, computer-controlled from private backyards or rooftop observatories, speckled the nation. Many could zoom quickly toward any patch of sky-hobbyists with access to better instrumentation than earlier generations of top experts could have imagined. Dotted lines appeared. Each showed the viewing angle of some home-taught astronomer, ecologist, or meteorologist, turning a hand- or kit-made instrument toward the majestic cigar shape of the Spirit of Chula Vista…

… which had passed Arlington and Pentagon City, following its faithful tug into a final tracked loop, turning to approach the dedicated zeppelin port that served Washington, D.C.

“Yes, Tor. There is helium.

“Quite a lot of it, in fact.

“A plume that stretches at least a hundred klicks behind the Spirit . No one noticed before, because helium is inert and utterly safe, so no environmental monitors were tuned to look for it.”

The voice was grim. Much less individualized. With ad hoc membership levels suddenly skyrocketing, summaries and updates must be spewing at incredible pace.

“Your suspicion appears to be well based.

“Extrapolating the rate of helium loss backward in time, more than half of the Spirit of Chula Vista ’s original supply of that gas may have been lost by now…”