"That may be an optical illusion," said the science master. "Our own moon, seen at a distance of forty million miles, would appear to be intersected very much as Mars seems to be. The truth is, we can never get Mars to stand still long enough to get a definite photograph!"
"From Jupiter?" suggested Chap, now thoroughly interested.
Again Mr. Colson smiled.
"A semi-molten mass on which life could not possibly exist. Nor could it come from Saturn," he went on tantalizingly, "nor from Venus."
"Then where on earth do these signals come from?" blurted Chap, and this time Mr. Colson laughed outright.
As they sat at tea, Elsie glanced out admiringly upon the brilliant-hued garden that was visible through the big window, and then she saw something which filled her with astonishment. Two men had come into view round the end of a square-cut hedge. One was the man they had seen half-an-hour previously--the commonplace little fellow who had claimed to be