_"If you had a really big knife -- "_

"Cut! Jesus, Greene, is this the best you can find? Have you heard back from the organic chem guys yet?"

"Their preliminary analysis just came in," Alan said. "As best they can guess -- and I'm cutting through a lot of clutter here -- the rain you went through wasn't pure methane."

"No shit, Sherlock."

"They're assuming that whitish deposit you found on the rings and ropes is your culprit. They can't agree on what it is, but they think it underwent a chemical reaction with the material of your balloon and sealed the rip panel shut."

"I thought this was supposed to be a pretty nonreactive environment."

"It is. But your balloon runs off your suit's waste heat. The air in it is several degrees above the melting-point of ice. That's the equivalent of a blast furnace, here on Titan. Enough energy to run any number of amazing reactions. You haven't stopped tugging on the vent rope?"

"I'm tugging away right now. When one arm gets sore, I switch arms."

"Good girl. I know how tired you must be."

"Take a break from the voice-posts," Consuelo suggested, "and check out the results we're getting from the robofish. It's giving us some really interesting stuff."

So she did. And for a time it distracted her, just as they'd hoped. There was a lot more ethane and propane than their models had predicted, and surprisingly less methane. The mix of fractions was nothing like what she'd expected. She had learned just enough chemistry to guess at some of the implications of the data being generated, but not enough to put it all together. Still tugging at the ropes in the sequence uploaded by the engineers in Toronto, she scrolled up the chart of hydrocarbons dissolved in the lake.

Solute: Solute mole fraction

Ethyne: 4.0 x 10-4

Propyne: 4.4 x 10-5