The wall of the tunnel grew visibly moist; Rajendra reached out and trailed his fingers through the chalky fluid. Water and nutrients penetrated every part of the island (even the center, although the dry, hard surface layer was thickest there). It didn't matter that the rock here would never be mined—and the fact that the tunnel remained unhealed showed that this region had been explicitly programmed against regrowth. The lithophiles were still indispensable; the heartrock could never be allowed to die.
I began to make out tiny bubbles forming in the fluid clinging to the wall—and then, deeper still, visible effervescence. Beyond the edges of the guyot, Stateless was unsupported from below—and a solid limestone overhang forty kilometers long, strengthened by biopolymers or not, would have snapped in an instant. The guyot was a useful anchor, and it bore some of the load, but most of the island simply had to
The air in the foam was under pressure, though: from the rock above, and—below sea level—from the surrounding water trying to force its way in. Air was constantly being lost to diffusion through the rock; the wind blasting out of this tunnel was the accumulated leakage from hundreds of square meters, but the same thing was happening, less dramatically, everywhere.
The lithophiles prevented Stateless from collapsing like a punctured lung, and sinking like a drowned sponge. Plenty of natural organisms were proficient at making gas, but they tended to excrete products you wouldn't want wafting out of the ground in vast amounts, like methane or hydrogen sulphide. The lithophiles consumed water and carbon dioxide (mostly dissolved) to make carbohydrates and oxygen (mostly undissolved)—and because they manufactured "oxygen-deficient" carbohydrates (like deoxyribose), they released more oxygen than they took in carbon dioxide, adding to the net increase in pressure.
All of this required energy as well as raw materials; the lithophiles, living in darkness, needed to be fed. The nutrients they consumed and the products they excreted were part of a cycle which stretched out to the reefs and beyond; ultimately, sunlight on distant water powered everything they did.
Soon the surface was frothing and boiling, spraying calcareous droplets toward the camera like spittle. And it finally dawned on me that I'd been utterly mistaken: the dive had nothing to do with Edenite notions of "modern tribalism." Whatever courage it required was incidental; that wasn't being valued for its own sake. The point was to descend through the palpable exhalation of the rock, and to see with your own eyes what Stateless
Rajendra's hand appeared at the border of the image as he fitted the mouthpiece and switched on the air supply. Of course: all this seeping liquid would build up at the bottom of the tunnel. He glanced down once, at what looked like a dark, sulphurous pool, boiling with volcanic heat; in fact, it was probably chilly and almost odorless. Munroe had been right about one thing: you really had to be there. What's more… the tunnel wind would be weaker at this depth than at the surface, because much of the leaking rock contributing to the total airflow was now overhead. Rajendra would have no trouble noticing the difference—but the view, alone, of gas escaping at ever greater pressure, suggested exactly the opposite.
As the camera plunged beneath the surface, the image flickered and then switched to lower resolution. Even through the turbulent, cloudy water, I could still catch occasional glimpses of the tunnel wall—or at least the wall of bubbles streaming out of the rock. It was a weird, disorienting sight—it almost looked as if the water was so acidic that it was dissolving the limestone right before my eyes… but once again, that impression would have been instantly untenable if I'd been down there in person, swimming in the stuff.
The resolution dropped again, and then the frame rate fell; the picture became a series of stills in rapid succession as the camera struggled to maintain contact. Sound came through clearly enough, though I probably wouldn't have recognized distortion in the noise of bubbles breaking against a scuba mask. Rajendra glanced down; the view showed ten thousand pearls of oxygen streaming up through opalescent water— and nothing more distant than his knees. I thought I heard him inhaling sharply, tensing himself in preparation for touching the bottom—and then I almost sent the notepad tumbling down after him.
One still showed a startled, bright red fish staring straight into the camera. In the next image, it was gone.
