. Gibson and Xavier, the one disdaining rest and the other needing
none, used the time to run a test analysis on the bones brought in from
the lakeside.

The results of that analysis were more astonishing than illuminating.

A majority of the fragments had been exposed to climatic action for some
ten years. A smaller lot averaged twenty years; and a few odd chips,
preserved by long burial under alluvial silt, thirty.

"The older natives died at ten-year intervals, then," Stryker said. "And
in considerable numbers; the tribe must have been cut to half strength
each time. But why?" He frowned unhappily, fishing for opinion. "Gib,
can it really be a perversion of religious custom dreamed up by the
Hymenops to keep their slaves under control? A sort of festival of
sacrifice every decade, climaxing in tribal decimation?"

"Maybe they combine godliness with gluttony," Farrell put in, unasked.
"Maybe their orgy runs more to long pig than to piety."

He stood up, wincing at the pain, and was hobbling toward his sleeping
cubicle when Gibson's answer to Stryker's question stopped him with a
cold prickle along his spine.

"We'll know within twenty-four hours," Gibson said. "Since both the
decimations and the winter darkness periods seem to follow the same
cycle, I'd say there's a definite relationship."

* * * * *

For once Farrell's cubicle, soundproofed and comfortable, brought him
only a fitful imitation of sleep, an intermittent dozing that wavered
endlessly between nightmare and wakefulness. When he crawled out again,
hours later, he found Xavier waiting for him alone with a thermo-bulb of
hot coffee. Stryker and Gibson, the mechanical said blandly, had seen no
need of waking him, and had gone out alone on a more extensive tour of
investigation.

The hours dragged interminably. Farrell uncased his beloved accordion,
but could not bear the sound of it; he tried his sketch-book, and could
summon to mind no better subjects than drab miasmic bogs and steaming
mudflats. He discarded the idea of chess with Xavier without even
weighing it--he would not have lasted past the fourth move, and both he
and the mechanical knew it.

He was reduced finally to limping about the ship on his bandaged foot,
searching for some routine task left undone and finding nothing. He even
went so far as to make a below-decks check on the ship's
matter-synthesizer, an indispensable unit designed for the conversion