“Anything else in the atmosphere?” asked Cimon.

“Water vapor and dust. I suppose there are a few million airborne spores of various virulent diseases per cubic centimeter in addition to that.” He said it lightly enough, but there was a stir in the room. More than one of the bystanders looked as though he were holding his breath.

Vernadsky shrugged and said, “Don’t worry about it for now. My analyzer washes out dust and spores quite thoroughly. But then, that’s not my angle. I suggest Rodriguez grow his cultures under glass right away. Good thick glass.”

Mark Annuncio wandered everywhere. His eves shone as he listened, and he pressed himself forward to hear better. The group suffered him to do so with various degrees of reluctance, in accordance with individual personalities and temperaments. None spoke to him.

Sheffield stayed close to Mark. He scarcely spoke, either. He bent all his effort on remaining in the background of Mark’s consciousness. He wanted to refrain from giving Mark the feeling of being haunted by himself; give the boy the illusion of freedom, instead. He wanted to seem to be there, each time, by accident only.

It was a most unsuccessful pretense, he felt, but what could he do? He had to keep the kid from gelling into trouble.

Miguel Antonio Lopez y Rodriguez—microbiologist; small, tawny, with intensely black hair which he wore rather long, and with a reputation which he did nothing to discourage, of being a Latin in the grand style as far as the ladies were concerned—cultured the dust from Vernadsky’s gas-analyzer trap with a combination of precision and respectful delicacy.

“Nothing,” he said, eventually. “What foolish growths I get look harmless.”

It was suggested that Junior’s bacteria need not necessarily look harmful; that toxins and metabolic processes could not be analyzed by eye, even by microscopic eye.

This was met with hot contempt, as almost an invasion of professional function. He said, with an eyebrow lifted, “One gets a feeling for these things. When one has seen as much of the microcosm as I have, one can sense danger—or lack of danger.”