estimate of his speed.
He'd jury-rigged a kind of control on the hull field, so he could aim
the hulk easily enough. He'd only have to get within signaling range,
anyway. An Earth ship would pick him up.

_If there was any Earth left by the time he got there._

He forced his mind away from thinking about that.

It was not until he reached the last spool of microfilm that his
situation was forcibly brought to focus in his mind. Thus far, he had
thought only about saving himself. But the note at the end of the spool
made him realize that there were others to save.

The note said: _These reports must reach Earth before 22 June 2287.
After that, it will be too late._

_22 June!_

That was--let's see....

_This is the eighteenth of September_, he thought, _June of next year
is--nine months away. Surely I can make it in that time. I've got to._

The only question was, how fast was the hulk of the _Shane_ moving?

It took him three days to get the answer accurately. He knew the
strength of the field around the ship, and he knew the approximate
thrust of the single engine by that time. He had also measured the
motions of some of the nearer stars. Thank heaven he was a navigator and
not a mechanic or something! At least he knew the direction and distance
to Earth, and he knew the distance of the brighter stars from where the
ship was.

He had two checks to use, then. Star motion against engine thrust and
field strength. He checked them. And rechecked them. And hated the
answer.

He would arrive in the vicinity of Sol some time in late July--a full
month too late.

What could he do? Increase the output of the engine? No. It was doing
the best it could now. Even shutting off the lights wouldn't help
anything; they were a microscopic drain on that engine.

He tried to think, tried to reason out a solution, but nothing would
come. He found time to curse the fool who had decided the shielding on
the lifeboat would have to be removed and repaired. That little craft,
with its lighter mass and more powerful field concentration, could make
the trip in ten days.

The only trouble was that ten days in that radiation hell would be
impossible. He'd be a very well-preserved corpse in half that time, and
there'd be no one aboard to guide her.

Maybe he could get one of the other engines going! Sure. He _must_ be
able to get one more going, somehow. Anything to cut down on that time!

He went back to the engines again, look