“Who was right, you or Indigo?”

“Both of us.”

“You can’t both be right.”

“We are. That’s what’s so strange. Do you know what hydrogen is?”

“Of course I do.”

“But did you know that it can come in two forms? One of them is an atom where the nucleus is a proton, and there’s one electron in orbit around it. That’s the common form. But you can also have a form called deuterium , which has a nucleus, a deuteron , with one proton and one neutron. You still have one electron, so the chemical properties of deuterium are the same as hydrogen.”

“So?”

“So you can make a molecule, a water molecule, with two atoms of hydrogen and one atom of oxygen. Or you can, just as well, make a kind of water molecule with two atoms of deuterium and one atom of oxygen. It’s been known for centuries, it’s called deuterium oxide, or heavy water — and it’s about eleven percent more dense than ordinary water. It can be used just like ordinary water. You can bathe in it, you can cook with it. I’m pretty sure you can drink it, at least some, and not notice a difference. That’s what we have outside the ship. We are sitting at the bottom of an ocean, but it’s a heavy-water ocean.”

“Are you sure of this?”

“Sure as I can be until I do the final tests of molecular weight. But assuming I’m right, it’s good news. We can wander around outside in our suits and be quite safe. If we run low on water, we can even drink some. I suspect there are differences in diffusivity rates from ordinary water, and that could have long-term fatal effects, but …”

She was laughing at him. Bony stopped talking. “I’m sorry. I get carried away. I’m boring you, aren’t I?”

“Of course you’re not. I get such a kick out of watching you when an idea catches fire. You light up like a little kid.”

“Sure. Thanks.”

“Oh, stop that.” Liddy pulled out the little chair on the other side of the desk and squeezed onto it. “Can’t you recognize a compliment when you hear one? Now what are you doing?”

What Bony was doing, not very successfully, was crumpling up candy wrappers and trying to count them at the same time. He was amazed at their number. “I tend to eat when I’m working.”

“Then you must have been absolutely slaving. And I interrupted you. I’ll go away.”

“No. You can help me. If you don’t mind.”

“I can’t do that stuff to save my life.” Liddy’s wave took in the display of schematics, the computer dialog, and Bony’s random notes on pressures and volumes.

“I don’t mean calculations. I need practical help. Now we know what’s out there, I’m ready to consider an EVA — a trip outside the ship. To do that, we have to make one of the airlocks work, underwater. I think I know how, but it’s a two-person job. Are you free?”

“I think so.” Liddy caught Bony’s unconscious glance upward. “Don’t worry, he’ll snore for at least another hour. He always does afterwards.”

“I don’t believe it.”

“Indigo sleeps a lot.”

“I mean, I don’t understand how he’s able to sleep now . We’re lost on the seabed of an unknown planet when we ought to be in open space. We’re in a ship never designed for anything but space operations. We have no idea how we came here, or if we’ll ever be able to get away. And he’s asleep. How can anybody sleep at a time like this?”

“You really don’t know, do you?” Liddy, head to one side, was studying Bony. “I can tell you’ve never been rich. Neither have I, but I’ve been around wealthy people. Things are different when you’re rich. Indigo bought me, you know.”

“That’s terrible.” Bony said the words automatically, but he was in some ways relieved. At least Liddy wasn’t Friday Indigo’s mate by choice.

“Being bought is much worse the first time it happens. But that’s not my point. My point is, Indigo bought you, too.”

“Never. I’m a free man.”

“Then what are you doing, working while he’s sleeping? What are you doing here at all, lost in the Geyser Swirl?”

Bony had a good answer to the last question, but he was not willing to give it. He stood up. “Come on. Let’s go and work on the airlock while he’s still asleep.”

“You’re trying to change the subject.” Liddy followed him down the ladder. “Let me explain something to you. When you’re born rich, like Friday Indigo, you don’t do things. You buy things. And those things include more than material objects. You buy people. You buy services. You buy reassurance. Friday Indigo is using his money now to buy peace of mind. He bought your services, so he expects you to save the ship and him and find a way home. Why shouldn’t he sleep easy?”

“He’s crazy.” Bony was in the airlock, moving to one side of the small compartment so that Liddy could join him. There was barely space for two people. “I don’t even know if we can get outside this ship.”

“Maybe he is crazy. But you know what?” Liddy stopped right in front of him, their faces six inches apart and eye to eye. “I agree with him. I expect you to save me, too.”

Bony felt a curious heat and pressure in his belly, as though the inside was being cooked in a microwave oven at high setting. He stepped hurriedly backward, and a faucet for the delivery of air to the lock poked him hard in the small of his back. He exclaimed in pain.

Liddy laughed. “What are you doing? I’m not infectious.”

“If Indigo comes down here, and sees us together like this …”

“Like what? You haven’t touched me. And he was the one who told me to go with you and try to be useful for a change.”

“He’s an absolute bastard.”

“Everything’s relative. I saw a lot worse when I was growing up.”

“Where was that?” Bony turned away, partly to study the hatch design and partly to escape Liddy’s eyes. “I know you said you lived down on Earth.”

“I did, but I’m not sure it would mean anything to you. Did you ever hear of a place called the Shambles?”

Bony couldn’t help staring at her. “No.”

“Yes, you did.” She cocked her head to one side. “Your face gives you away. Why won’t you tell me the truth?”

“I’ve heard bad things about the Shambles. It’s supposed to be the worst of the Terran basement warrens.”

“It’s like most places, some parts better than others. I was lucky. I was educated at one of the better schools.”

“Which one was that?” Bony knew more about the Shambles than he was willing to admit, and schools were not what came first to mind.

“The Leah Rainbow Academy for the Daughters of Gentlefolk.”

“My God.” It didn’t need his face to give him away this time, the words popped right out.

“Uh-oh.” Liddy grimaced. “You’ve heard of that, too. Then I’ve said too much. I’m sorry.”

“It’s not your fault.”

“I had no idea, not one in a million off-Earthers has heard of it.”

“I have, because—” Bony was on the point of telling the truth, but he caught himself just in time “—because I’ve read a lot about Earth.”

“That’s even more peculiar. I didn’t think anybody wrote about the Academy. Customers normally came through a personal recommendation.”

“How did you come to be living there? At the Leah Rainbow Academy, I mean.” Bony sank down on his knees, studying the geometry of the lock. The internal air pressure was the same as in the rest of the ship, one standard atmosphere. The hatch was facing almost directly downward. When they closed the inner hatch, sealing themselves off from the ship, and opened the outer hatch just a crack, one of two things would happen. If the outside water pressure was less than the internal air pressure, some air would bubble out. If the outside pressure was greater, water would enter until the pressures equalized.

Were there any other possibilities? Well, there was always the improbable case where the inside and outside pressures were exactly equal, but chances were strongly against that. And there was the case where Bony had forgotten to take account of some crucial variable, and as the hatch was cracked open something totally unforeseen happened.