Junior dug one of the counters out of the supply cabinet and aimed the pickup at Fweep. The counter began to hum. As Fweep approached, the hum rose in pitch. As it passed, the hum dropped.
Junior looked at the counter's dial. "He's radioactive, all right. Not much, but enough. But where does he get the radioactive material?"
"He uses ordinary matter," Four said. "He must have used up the few deposits of natural radioactives a long time ago."
"He uses ordinary substances on an atomic level?" Junior said unbelievingly.
Four nodded. "And that 'skin' of his—whatever it is he uses for skin—is more efficient in stopping particle emissions than several feet of lead."
Fred studied Fweep thoughtfully. "Maybe we could feed him enough enriched uranium from the pile to put him over the critical mass."
"And blow him up? I don't think it's possible, but even if it were, it might be a trifle more than disastrous for us." Four giggled at the thought.
Joyce glared at him furiously. "Four! Act your age! We've got to do something with him. It's preposterous that we should be detained here at the whim of a mere blob!"
"I don't figure it's a whim," Grampa said. "Circular gravity is what he's got to have for one reason or another, so he just naturally bends the space-time continuum around him—conscious or subconscious, I don't know. But protoplasm is always more efficient than machines, so the flivver won't move."