of Earth's ships could equip
themselves with spray guns and squirt citric acid and watch the
Steel-Blues fade away.

It sounded almost silly to Jon Karyl. The fruit acid of Earth to repel
these invaders--it doesn't sound possible. That couldn't be the answer.

Citric acid wasn't the answer, Jon Karyl discovered a week later.

The Steel-Blue who had captured him in the power room of the service
station came in to examine him.

"You're still holding out, I see," he observed after poking Jon in every
sensitive part of his body.

"I'll suggest to No. 1 that we increase the power of the--ah--hemlock.
How do you feel?"

Between the rich oxygen and the dizziness of hunger, Jon was a bit
delirious. But he answered honestly enough: "My guts feel as if they're
chewing each other up. My bones ache. My joints creak. I can't
coordinate I'm so hungry."

"That is the hemlock," Steel-Blue said.

It was when he quaffed the new and stronger draught that Jon knew that
his hope that it was citric acid was squelched.

The acid taste was weaker which meant that the citric acid was the
diluting liquid. It was the liquid he couldn't taste beneath the tang of
the citric acid that was the corrosive acid.

On the fourteenth day, Jon was so weak he didn't feel much like moving
around. He let the cylinder feed him the hemlock.

No. 1 came again to see him, and went away chuckling, "Decrease the
dilution. This Earthman at last is beginning to suffer."

* * * * *

Staying alive had now become a fetish with Jon.

On the sixteenth day, the Earthman realized that the Steel-Blues also
were waiting for the SP ship.

The extra-terrestrials had repaired the blue ship where the service
station atomic ray had struck. And they were doing a little target
practice with plastic bubbles only a few miles above the asteroid.

When his chronometer clocked off the beginning of the twenty-first day,
Jon received a tumbler of the hemlock from the hands of No. 1 himself.

"It is the hemlock," he chuckled, "undiluted. Drink it and your torture
is over. You will die before your SP ship is destroyed.

"We have played with you long enough. Today we begin to toy with your SP
ship. Drink up, Earthman, drink to enslavement."

Weak though he was Jon lunged to his feet, spilling the tumbler of
liquid. It ran cool along the plastic arm of his space suit. He changed
his mind about throwing the contents on No. 1.

With a smile