"True. But we had no basis for prediction. After all, it would have been taking a chance. Suppose that the instability had caused a nova? Epitaphs are nice but none the less final. We left hundreds of years before the solar proximity. Now we know that we might have survived, but as you know, we can not swerve Ertene's course readily and though we are slowly turning, the race may have died out and gone for a galactic eon before we could return. Once the race dies out--or the interest in returning to a certain sun back there in the depths of the galaxy dies--we will cease to turn. We may find a haven somewhere, before then." "You were speaking of years," said Guy. "Was that a loose reference or were you approximating my conception of a year?" "A _year_ is a loose term indeed, no matter by whom it is used," said Charalas. "To you, it is three hundred and sixty-five, and about a quarter, days. A day is one revolution of Terra. From Mars, say, a Terran year is something else entirely. Mars, of course, is not too good an example for its sidereal day is very close to Terra's. But your Venus, with its eighteen hour day--eighteen Terran hours--sees Terra's year as four hundred eighty-six, plus, days. On Ertene, we have no year. We had one, once. It was composed of four hundred twelve point seven zero four two two nine three one days, sidereal. Now, our day is different, since the length of the solar day depends upon the progression of the planet about its luminary. Our luminary behaves as a moon with a high ecliptic-angle as I have explained. No, Guy, I have been mentally converting my _year_ to your year, by crude approximation." The next panel was an ornate painting of the Ertinian system, showing--out of scale for artistic purpose--the planets and sun, with Ertene drawing away in a long spiral. "For many years we pursued that spiral, withdrawing from the sun by slow degrees. Then we broke free." Charalas indicated the panel which showed Ertene in the foreground while the clustered system was far behind. They passed from panel to panel, all of which were interesting to Guy Maynard. There was a series of the first star contacted by Ertene. It was a small system, cold and forbidding, or hot and equally forbidding. The outer planets were in the grip of frozen air, and the inner planets bubbled in moltenness "This system was too far out of line to turn. It was our first star, and we might have stayed in youthfulness. Now, we know better." The next panel showed a dimly-lighted landscape; a portrayal of Ertene without its synthetic sun. The luminous sky was beautiful in a nocturnal sort of way; to Guy it was slightly nostalgic for some unknown reason, at any rate it was the soul of sadness, that landscape.