He rose and went to the forward port, staring dully down at the uprushing sandy wastes and trying to recall what glorious thing it was that he had been thinking. Or had it been only a dream? Somewhere in the farthest recess of his blunted consciousness a thought formed and floated like a bubble up into his awareness; but like a bubble it burst, and its meaning was lost on him. _There were Tenants on Earth_, it said. _Why not on Mars, too?_