Right now it was even more so, with a big bag of goldbeater's skin-scraped whale intestine-hanging from the ceiling. A tube ran down from that to the Cessna engine mounted on a timber framework in the middle of the concrete floor. The rest of the team gathered around, in stained blue Coast Guard coveralls or the equally greasy unbleached gray cotton that Seahaven Engineering favored. The hangar smelled of hot whale-oil lubricant, and other things less familiar these days-gasoline fumes and a faint, nose-rasping hint of ozone.

Another deep breath, and she pushed the ignition button. The engine coughed, sputtered, blatted… and then settled down to a steady roar. Some of the watchers covered their ears, unused to something Nantucket had heard little of since the Event-an internal combustion engine at full throttle.

"Great!" Vicki shouted. "Let's take her up and down, and vary the mix. Standby!"

The engine snarled, coughed again as the mixture of hydrogen from the gasbag and methanol altered. Four hundred fifty horsepower, or thereabouts. About what it had put out in its first incarnation as half the engines on a Cessna puddle jumper.

"Get that adjusted!" Vicki said. The tests continued, sweating-hot work on a summer's day, until at last she tripped the switch and wiped her hands again, smiling fondly as the engine sputtered into silence.

"Damn, you know, I think this is going to work," she said.

"No reason why it shouldn't," Leaton said. "Methanol, hydrogen, gasoline-it's all an inflammable gas by the time it reaches the piston."

Vicki chuckled indulgently; she was twenty-seven, nearly two decades younger than Leaton, and she still felt motherly toward him sometimes. One reason was the otherworldly way he had of forgetting everything but the task at hand.

"I meant the whole Emancipator program, not just the engine," she said.

"Oh. Oh, yes, that too. All right, people, break for lunch!"

He and Vicki and a young man in Guard fatigues walked over to a sloping table by the concrete-block wall.