if you had been
hit two hours ago instead of two weeks."

"Yeah, I guess I'd better." Ken arose, feeling weak and dizzy. "Can you
get that report typed for Dad tonight? It would be good for him to be
able to take it to the lab with him in the morning."

"I'll get it done," said Maria. "You get off to bed."

As much as he rebelled against it, Ken was forced to spend the next two
days in bed. Dr. Adams allowed him to be up no more than a few hours on
the third day. "I'm afraid you took a worse beating than any of us
thought," the doctor said. "You'll just have to coast for a while."

It was as he was finally getting out of bed again that he heard Art
Matthews, when the mechanic came to the door and spoke with Ken's
mother.

"This is awfully important," Art said. "I wish you'd ask him if he
doesn't feel like seeing me for just a minute."

"He's had a bad relapse, and the doctor says he has to be kept very
quiet for a day or two longer."

Dressed, except for his shoes, Ken went to the hall and leaned over the
stair railing. "I'll be down in just a minute, Art. It's okay, Mom. I'm
feeling good today."

"Ken! You shouldn't!" his mother protested.

In a moment he had his shoes on and was racing down the stairs. "What's
happened, Art? Anything gone wrong?"

The mechanic looked downcast. "Everything! We got the Norton elevator
motor and hooked it up with the gas engine. It ran fine for a couple of
days, and we got a lot of batteries charged up."

"Then it quit," said Ken.

"Yeah--how did you know?"

"I've been afraid we had missed one bet. It just isn't enough to supply
filtered air to the engines built of new parts. The parts themselves are
already contaminated with the dust. As soon as they go into operation,
we have the same old business, all over again.

"Unless some means of decontamination can be found these new parts are
no better than the old ones."

"Some of these parts were wrapped in tissue paper and sealed in
cardboard boxes!" Art protested. "How could enough dust get to them to
ruin them?"

"The dust has a way of getting into almost any corner it wants to," said
Ken. "Dad and the others have found it has a tremendous affinity for
metals, so it seeps through cracks and sticks. It never moves off once
it hits a piece of metal. What parts of the engine froze?"

"Pistons, bearings--just like all the rest."

"The generator shaft, too?"

Art nodded. "It might have gone a few more revolutions. It