Finally clouds of mirrored life-forms rolled upwards. The treacherous sky was locked out... but every stray photon of the planet's internal heat was trapped.

"I don't get it, Michael," Wyman said. "If they're so short of heat why aren't they all jet-black?"

"Because perfect absorbers of heat are perfect emitters as well," I said. "High school physics, Wyman. While perfect reflectors are also the best heat containers. See?"

"...Yeah. I think so."

"And anyway, who cares about the why of it? Wyman, it's... beautiful."

"I think you've got a visitor."

A five-foot bauble had separated from the forest and now came flying over the sequined field. In its mirrored epidermis I could see my own spectral face. Taped to that hide was a standard translator box. A similar box was fixed to the pod floor; now it crackled to life. "You are Dr. Michael Luce. I understand you represent a Wyman, of Earth. You are welcome here," said the Silver Ghost. "I work with the Sink Ambassador's office."

"The Sink?" I whispered.

"The Heat Sink, Luce. The sky. I am Wyman. Thank you for meeting us. Do you know what I wish to discuss?"

"Of course. Our respective expeditions to the lithium site." The truncated spheroid bobbed, as if amused. "We can make an educated guess about what you seek to achieve here, Mr. Wyman. What we do not know yet is the price you'll ask."

Wyman laughed respectfully.

I felt bewildered. "Sorry to butt in," I said, "but what are you talking about? We're here to discuss a pooling of resources. Aren't we? So that humans and Ghosts end up sharing--"

The Ghost interrupted gently. "Dr. Luce, your employer is hoping that we will offer to buy him out. You see, Wyman's motivation is the exploitation of human technology for personal profit. If he proceeds with your expedition he has the chance of unknown profit at high risk. However, a sell-out now would give him a fat profit at no further risk."

Wyman said nothing.

"But," I said, "a sell-out would give the Ghosts exclusive access to the lithium knowledge. All that creation science you told me about, Wyman... I mean no offense," I said to the Ghost, "but this seems a betrayal of our race."

"I doubt that is a factor in his calculation, Doctor," said the Ghost.

I laughed dryly. "Sounds like they know you too well, Wyman."

"So what's your answer?" Wyman growled.

"I'm afraid you have nothing to sell, Mr. Wyman. Our vessel will arrive at the lithium-7 site in..." A hiss from the translator box. "Fourteen standard days."

"See this ship? It will be there in ten."

The Ghost was swelling and subsiding; highlights moved hypnotically over its flesh. "Powered by your supersymmetry drive. We are not excited by the possibility that it will work--"

"How can you say that?" I snapped, my pride obscurely wounded. "Have you investigated it?"