"Doesn't matter. Get going."

It had taken Jeffer the Scientist a fifth of a day to cross three klomters of line.

Free-fall brought back memories. When Quinn Tribe was lost in the sky after Dalton-Quinn Tree came apart, his crew would have given eyes and limbs to reach a pond. Fourteen years later, the grandmother of all ponds floated three klomters from Citizens Tree; and now their main problem was to get rid of most of it. Jeffer wondered if the children appreciated their wealth.

Perhaps they did. Most of Citizens Tree, thirty naked adults and children, had come to swim in that shimmering sphere of water.

There was no foliage on the high trunk. It was thick rough bark, with fissures deep enough to hide a man. Jeffer found and donned his tunic and pants, then anchored his toes in a crevice and thrust to send himself gliding out along the bark, toward the CARM.

The lift cable ended two hundred meters short of the CARM's dock. The citizens may have feared that careless use of the CARM might spray fire across a rising cage. More likely, they feared the CARM itself. They would not lightly come too near that ancient scientific thing.

The CARM was old science. It was roughly brickshaped, four meters by ten by thirty-two, and made of starstuff: metal and glass and plastic, sheathed with darkly luminous stuff that took the energy from sunlight. The bulk of it was tanks for hydrogen and oxygen and water. Nostrils at the aft end-four at each corner, and a larger one in the middle-would spurt blue fire on command.

They had neglected the CARM of late, and Jeffer accepted some of the blame. The CARM made two "flavors" of fuel out of water and the power in the batteries. The batteries held their full scientific charge-they filled themselves, somehow, as long as sunlight could reach the CARM's glassy surface-but the hydrogen and oxygen tanks were almost empty. It was high time they filled the water tank.

The CARM's bow was moored in a dock of wooden beams. Double doors led into a hut with cradles for passengers, moorings for cargo, and a broad transparent window. The window looked forth on nothing but bark. Ventral to the window was a gray sheet of glass and a row of colored buttons.

Jeffer went forward. A touch of a blue button lit the gray glass panel. Blue governed what moved the CARM: the motors, the two flavors of fuel supply, the water tank, fuel flow. Jeffer read the blue script:

H2: 0,518

Oz: 0,360

HzO: 0,001

POWER: 8,872

The batteries danced with energy. Why not? The CARM wasn't using power. Nobody in Citizens Tree had bothered to fill the water tank in seven years; so power wasn't needed to split water into hydrogen and oxygen. The water tank was virtually dry.