wheels go around so we can
move, and that is as much of the theory of the steam engine as you are
going to get from me. Maybe you can understand this better--only I can
get you safely away from here. Therefore, you will stay and do as I
say or I will beat your brains in. Clear?"

Snarbi nodded dumbly.

"Fine. All you have to do is sit here and look at this little green
disk, see it? If it should pop out before I come back turn _this_
handle in _this_ direction. Clear enough? That way the safety valve
won't blow and wake the whole country and we'll still have a head of
steam."

[Illustration]

Jason went out past the still-silent sentry and headed back towards
the refinery station. Instead of a club or a dagger he was armed with
a well tempered broadsword that he had managed to manufacture under
the noses of the guards. They had examined everything he brought from
the worksite, since he had been working in the evenings in his room,
but ignored everything he manufactured as being beyond their
comprehension. This primordial mental attitude had been of immense
value for in addition to the sword he carried a sack of molotails, a
simple weapon of assault whose origins were lost in pre-history. Small
crocks were filled with the most combustible of the refinery's
fractions and wrapped around outside with cloth that he had soaked in
the same liquid. The stench made him dizzy and he hoped that they
would repay his efforts when the time came, since they were completely
untried. In use one lit the outer covering and threw them. The
crockery burst on impact and the fuse ignited the contents.
Theoretically.

Getting back in proved to be as easy as getting out, and Jason felt an
unmistakable twinge of regret. His subconscious had obviously been
hoping that there would be a disturbance and he would have to retreat
to save himself, his subconscious obviously being very short on
interest in saving the slave girl and his nemesis, particularly at the
risk of his own skin. His subconscious was disappointed. He was in the
building where his quarters lay, trying to peek around the corner to
see if a guard was at the door. There was, and he seemed to be dozing,
but something jerked him awake. He had heard nothing but he sniffed
the air and wrinkled his nose; the powerful smell of water-of-power
from Jason's molotails had roused him and he spotted Jason before he
could pull back.

"Who is there?" he shouted and advanced at a lumbering