Bureau specialists. Hilda was there, back in her box, and so was the deputy director; he had taken time out from his witch hunt to bring the robot in person-and also to let me know that this was all my fault, because if I had let him hide Beert away in Arlington, the way he wanted to, nobody would have known he was there.
He was wrong about that, of course-whoever leaked the story would have known about the sub, anyway, with or without Beert. I didn't argue. I spoke to Beert, ignoring everybody else. 'Something the Greatmother said has been nagging at me, something about the Others killing off rebellious races by poison gas. Do you remember what it was?'
'Of course, Dan,' he said promptly. 'It is part of our history. What do you wish to know?'
'What kind of gas? How do they get it to the planet?'
He waggled his neck at me. 'It isn't necessary to do that, Dan. On most planets like your own, such poisons are already there in the oceans. They need only to be released.'
And when I translated all that, the yelling began. There was no poison gas in the oceans, the experts insisted. There certainly was, Beert said stoutly, because the Greatmother of the Great-mother had said so. All right, snapped the experts, what poison are you talking about?
Naturally, Beert's words meant nothing when he answered. Nor did the robot's, when asked, but the robot had a better way of communicating. It drew pictures for us. A big dot with a little dot near it. A cluster of a dozen big dots, some filled in, some just circles, with six little dots near it.
It was the Bureau's chemical-warfare specialist who figured it out: 'They're diagrams of elements! Hydrogen and carbon!' And when the robot said there were four of the second diagram for every one of the first in this poison, the chemist blinked and smote her forehead with her hand and said, 'Of course!' It was the first time I had heard the word 'methane.'
PART ELEVEN
Methane
CHAPTER FIFTY-THREE
All right, I admit it. I should have thought of it before. Call it fatigue, call it too much going on-no, just call it that I screwed up. That's certainly what Hilda told me. It was what the deputy director told me, too, but he didn't waste any time. Two hours later he and Hilda and I, pumped up with the Bureau's wake-up pills, were watching the sun rise on the landing pad, where an oceanologist was tumbling off a VTOL from New Jersey. His name was Samuel Schiel, and he came from the Lamont-Doherty Institute-well, actually he came from his bed, because the deputy director's summons had come in the middle of the night- and he barely had time to catch his breath before Marcus Pell had whisked him into a conference room and the questioning had begun.
Pell didn't even sit down. He stood behind the big chair at the head of the table and turned on the man. 'You, what's your name, Schiel? Is this methane thing possible?'
Schiel was unfazed. He took a seat halfway down the long table, next to me, across from Hilda, looking around the room with interest. 'Possible?' he repeated ruminatively. 'Yes, in principle, Mr. Pell. Methane is a very common compound. It's the first member of the alkane hydrocarbons, a very simple molecule, and there's a great deal of it around in the form of clathrates, at least ten to the fifteenth cubic meters-Pardon? Oh.' He moved his lips for a moment, doing arithmetic. 'At least ten thousand million million cubic meters of the stuff, that is. Probably more. Much of it's locked up in permafrost in Asia and North America, but there's a tremendous amount on the sea bottoms. If you'd care to look-I asked my staff to transmit a map of the main deposits to me on the plane-'
He did something to the control for the screens at each place. While we were looking at them he investigated the coffee jug at his place, found it was full, poured himself a cup and waited for us to see what he was talking about.
I swallowed when I saw where the main deposits were: some of the biggest along the Atlantic Coast of the Americas, along the Pacific shore of Panama, the Bering Strait-I knew those areas well. 'That's exactly where the subs are concentrating,' I said.
Pell gave me a shut-up look; he had obviously figured that out for himself. 'How come you know all this?' he demanded, looking at Schiel.
Schiel put down his coffee cup. 'Why, the methane beds have been investigated quite thoroughly; there was some hope of tapping them as a replacement for petroleum resources. Methane is a very good, clean-burning fuel, but some of the best deposits are a kilometer deep or more, and they're not easy to exploit. Perhaps I should explain their physical nature?'
Pell sighed, reconciling himself to being lectured at by an expert but seeing no way out of it. 'Perhaps you goddam should,' he grumbled.
Schiel nodded briskly and went on. 'The methane content of the clathrates is hydrated,' he said. 'That means that each methane molecule is surrounded by a sort of cage of water molecules, in the form of ice under pressure. If the temperature rises or the pressure decreases, the clathrate disintegrates. When samples are trawled up from the sea bottom they begin to bubble and sizzle and fall apart even before they reach the surface, often quite explosively. Worse, there is some evidence that any attempt to exploit these resources for fuel may be quite dangerous. You see, under the clathrate beds there are trapped bodies of gaseous methane. When the crust is broken through, the methane gas can escape. In great volume, Mr. Pell. In which case it appears capable of turning the ocean itself into a sort of froth which is no longer dense enough to float a vessel. A Soviet drilling ship which was mysteriously lost many years ago is thought to have sunk when that happened, and there have been conjectures that such events, off the coast of the Carolinas, may have been responsible for some of the alleged disappearances in the so-called Bermuda Triangle.' He looked around the room. 'Is that what you wanted to know, Mr. Pell?'
The deputy director was frowning at the map. He stabbed at the Carolina coast. 'Those submarines,' he said. 'Could they be used to blow a hole in this clathrate cap thing?'
Schiel shrugged. 'I know nothing of the Scarecrow submarines,' he said, 'but if they could plant some very large mines, yes, I think so. That might not be necessary, though. If they simply disturbed the clathrates sufficiently, they could start a release, which might then sufficiently lower the pressure to cause a greater release, entraining more and more clathrates as they rise to the surface. Once started, it could be a runaway effect, increasing exponentially as long as the methane held out.'
Pell thought that over. 'That would be a pain in the ass,' he said at last, 'but it doesn't sound fatal. All right, they can turn some coastal waters into club soda for a while. We might lose some shipping, but so what? It wouldn't destroy the world.'
'Oh, Mr. Pell,' Schiel said forgivingly, 'but it quite well might. Once a large-scale release began-Well, similar events have already happened here on Earth, you know. For example, it is believed that one such might have ended the Ice Age.'
The deputy director blinked at him. 'What?'
Schiel nodded. 'That was twenty-two thousand years ago,' he said. 'Geologists have determined that there was a huge landslip in the western Mediterranean at that time. That was when the Ice Age was in full force; worldwide ocean levels were the lowest ever, the amount of ice the highest. This caused some sea bottom to be exposed in the Mediterranean basin around Sardinia. There were deposits of icy methane-containing hydrates there, as there are in many shallow seas. When the sea level dropped, the pressure on them fell, as I discussed. They began to release their methane; the methane lubricated the slide; the slide released more methane-we think about half a billion tons al-together, nearly doubling the amount of methane in the atmosphere at the time. And the world warmed up and the Ice Age ended. Methane is dangerous stuff, you see. And that was just one local release. Actually,' he said, sounding almost pleased to be able to tell us about it, 'there is some evidence that one of the great extinctions of the geologic past took place as the result of a larger event. It was when all the present
