"Well...." The captain turned blue with concentration. "The Council, in chartering the Earth Expedition, expressed a fear that the planet might prove unavailable for colonization, due to possible inimical life forms. It's so much nearer the Sun, and so moist, that we had anticipated just such a canalbank jungle as does exist; and it's possible that the pressure of evolutionary competition might develop strange and fearful creatures.... But, remember that we haven't seen even one of these 'fiends.'"
"De Long said that a great many of them are invisible."
"Hmm!" said the captain. "Of course, that's within the bounds of possibility, though not of probability; but before we came here I'd have said flying animals were improbable. We had best investigate."
"Eh?"
"It's simple. We'll merely put de Long under the lie detector."
I was struck by the beautiful simplicity of this idea, which should have been right in my province.
"I leave it to you to maneuver de Long into a position where we can use the detector without his knowledge," said the captain.
"Very well," I said joyfully.
It was not difficult to get de Long aboard the ship; he had never had a chance to satisfy his curiosity concerning it. I showed him through several of the cabins without doing anything to arouse his suspicions, and finally got him seated within the effective radius of the lie detector.