Hubbard answered patiently, “Two reasons. I don’t know whether, or how, pesticides like boric acid, chlordane, pyrethrum, or sodium fluoride will work on this species of roaches. More important, all of them take time, and we want to be in and out of that cave damn fast.”

The volunteer demanded again, “If carbon dioxide’s the best, why don’t we use it all the time?”

Russell Homer replied in a superior tone, offended that such a silly question should be put to a man like Dr. Peter Hubbard, “We’d knock ourselves out! Can’t you figure that out?”

Hubbard explained further. “The gas is just for knocking them out for a while, you see.” The man withdrew with reddened face. The scientist said, “The only danger I see is in our approaching the nest. We know there are guard roaches, and they are big and murderously dangerous, I promise you.”

A husky man scoffed. “I haven’t seen a damn ol’ cockroach yet could scare me!” To him and many of his company the reports of the morning were clear exaggerations, old-­maid’s lollygagging over some damn nuisance water bugs.

Amos Tarbell answered for Hubbard, with a grim smile. “You fellows will change your mind! Just take your orders from Dr. Hubbard here, and you’ll be all right.”

The scientist moved the sheriff aside. “Amos, when you shear off the top of the nest for me, the trick will be not to drop too much dirt inside.”

The sheriff told him, “I understand. Should be okay—shale there—should come away clean.”

“Then we’re all set,” Dr. Peter Hubbard said finally.

As the group left to dress and gather equipment, Eliza­beth asked Hubbard worriedly, “Do you really have to go down into the roaches, Peter? Wouldn’t pictures be enough?”

The man’s face went taut with his inner scholarly excitement and determination. “Liz, this is a fantastic opportunity to view a colony mutation at first hand. It’s something scientists everywhere need to know about! What I really regret is that the nest does have to be burned for the sake of the island. The least I can do is make the fullest examination and report possible.”

“What if the carbon dioxide doesn’t get all of them?” she persisted. “We know how powerful they are, whatever you’re wearing!”

“If there’s trouble, I’ll have a rope around me so the men can pull me right out.”

She tried again. “Why not use something like chloroform?”

Hubbard found it easy to be patient with Elizabeth, and answered her quietly. “Wanda and I had discussed it, and there are two negative reasons. Chloroform could possibly work on our protective clothing and, more important, it would kill the roaches before I had any chance to take any alive.”