"I fainted?"
"Sure you did. You couldn't help it. They hit like a ton of brick."
"They certainly do," he said ruefully.
"They can kill," I said. "I've seen them do it. The Niobians generate them naturally, and they can focus them fairly well. Probably this quality was one of their forms of defense against predators in their early days. It's a survival trait; and when there are enough natives present to augment the impulses they can be downright nasty."
Bergdorf nodded. "I know," he said. He stopped talking and looked out over the sun-drenched top of the overcast. "It looks like Tovan Harl wants to keep this oyster farm a private matter. In a way he's doing us a favor, but I'd still feel happier if I had one or two of those oysters."
"Why do you need them?"
"Well, I figured on getting a couple of the Navy's organic detectors and setting them for oyster protoplasm. You know how sensitive those gadgets are. There might be a small but significant change in oyster protoplasm since it has arrived here."
"Well, you don't need to worry," I said. "I put one of your pets in my pocket before the natives showed up, so you've got what you need." I pulled the oyster out and handed it to him. It didn't look any the worse for its recent rough treatment.
Bergdorf grinned. "I knew I could trust you, Chief. You're sneaky!"
I laughed at him.