“That part is plain.” Boudreau leaned on the desk, shoulders hunched, brooding over the notes he had made. “I tell you, however, I have watched each single galaxy we passed through, or in observation distance of, these months. I have grown familiar with their types. And gradually those types are changing.” He jerked his head at the viewscope. “That up ahead, for instance, it is of the irregular sort, like the Magellanic Clouds at home—”

“I daresay, in these parts, the Magellanic Clouds count as home,” Foxe-Jameson murmured.

Boudreau chose to ignore the aside. “It should have a high proportion of Population n stars,” he went on. “From here we should be able to see many individual blue giants. Instead, we see none.

“All the spectra I take, to the extent I can interpret them, they are becoming different from what is normal for the types. No kind of galaxy looks right any more.”

He raised his eyes. “Malcolm, what is happening?”

Foxe-Jameson appeared surprised. “Why’d you pick me to query?” he countered.

“I had only a vague impression at first,” Boudreau said. “I am not a real astronomer. Besides, I could not get accurate navigational sights. To obtain a value of tau, for instance, requires such a cat’s cradle of assumptions that— Bien, when I finally felt sure the nature of space was altering, I approached Charles Reymont. You know how he puts down panic-mongers, and he is correct in that. He told me to call in one of your team, quietly, and report the answer back to him.”

Foxe-Jameson chortled. “Why, you two pathetic beggars! Haven’t you anything else to stew about? Actually, I thought it’d be common knowledge. So common that none of us pros happened to mention it, starved though everyone is for fresh conversation. Makes a chap wonder what else he’s overlooking, eh?”

“Qu’est-ce que c’est?”

“Consider,” Foxe-Jameson said. He settled one thigh and buttock on the desk. “Stars evolve. They build heavier elements than hydrogen in thermonuclear reactions. If one is so big that it explodes, a supernova, at the end of its life, it scatters some of those atoms back into the interstellar medium. A more important process, though, if less spectacular, is the shedding of mass by smaller stars, the majority, in their red-giant stage on the way to extinction. New generations of stars and planets condense out of this enriched medium and add to it in their turn. Over the ages you get a rising proportion of metal-rich suns. That affects the over-all spectrum. But of course no star gives back more than a percentage of the material which formed it. Most matter stays locked in dense bodies, cooling toward absolute zero. So the interstellar medium becomes depleted. Space within the galaxies grows more clear. The rate of star formation declines.”

He gestured bow-ward. “Finally you reach a point where little or no further condensation is possible. The energetic, short-lived blue giants bum themselves out and have no successors. The galaxy’s luminous members are entirely dwarfs— at last nothing except cool, red, miserly Type Ms. Those are good for almost a hundred gigayears.