Suddenly the biggest thing in the
universe was the very tiniest.

There were suns, which were nearby, and there were stars which wereso far away that no way of telling their distance had any meaning.The suns had planets, most of which did not matter, but the ones thatdid count had seas and continents, and the continents had cities andhighways and spaceports. And people.

The people paid no attention to their insignificance. They built shipswhich went through emptiness beyond imagining, and they landed uponplanets and rebuilt them to their own liking. Suns flamed terribly,renting their impertinence, and storms swept across the planetsthey preëmpted, but the people built more strongly and were secure.Everything in the universe was bigger or stronger than the people,but they ignored the fact. They went about the businesses they hadcontrived for themselves.

They were not afraid of anything until somewhere on a certain smallplanet an infinitesimal single molecule changed itself.

It was one molecule among unthinkably many, upon one planet of onesolar system among uncountable star clusters. It was not exactly alive,but it acted as if it were, in which it was like all the importantmatter of the cosmos. It was actually a combination of two complicatedsubstances not too firmly joined together. When one of the partschanged, it became a new molecule. But, like the original one, it wasstill capable of a process called autocatalysis. It practiced thatprocess and catalyzed other molecules into existence, which in eachcase were duplicates of itself. Then mankind had to take notice, thoughit ignored flaming suns and monstrous storms and emptiness past belief.

Men called the new molecule a virus and gave it a name. They called itand its duplicates "chlorophage." And chlorophage was, to people, themost terrifying thing in the universe.

In a strictly temporary orbit around the planet Altaira, the StarQueen floated, while lift-ships brought passengers and cargo up toit. The ship was too large to be landed economically at an unimportantspaceport like Altaira. It was a very modern ship and it made theRegulus-to-Cassim run, which is five hundred light-years, in only fiftydays of Earthtime.

Now the lift-ships were busy. There was an unusual number of passengersto board the Star Queen at Altaira and an unusual number of them werewomen and children. The children tended to pudginess and the women hadthe dieted look of the wives of well-to-do men. Most of them lookedred-eyed, as if they had been crying.

One by one the lift-ships hooked onto the airlock of the Star Queenand delivered passengers and cargo to the ship. Presently the last ofthem was hooked on, and the last batch of passengers came through tothe liner, and the ship's doctor watched them stream past him.

His air was negligent, but he was actually impatient. Like mostdoctors, Nordenfeld approved of lean children and wiry women. They hadfewer things wrong with them and they responded better to treatment.Well, he was the doctor of the Star Queen...