A current of air came cool and refreshing from a branching tunnel in the rock. There was no lack of ventilation, as they well knew, throughout all the tortuous passages, but this came with a scent of outdoors that set both men a-tingle with hope. Jerry forgot even the dull ache in his arm as he breathed deep of this messenger from the outside. But exploration must wait. They needed to rest, to learn and to plan. They returned when Marahna called softly from the room. * * * * * Time had lost all its meaning. They could only guess at the hours that had passed since the hour they left their ship, could only make unanswered surmises as to where was the sun or how much was left of the long lunar day. They must escape--they would escape--but their one stroke for freedom must not be made when darkness and paralyzing cold should force them back into the hands of the enemy tribes. Marahna was with them much of the time, and always they struggled and strove with desperate concentration to grasp at the meanings of the thoughts she tried to convey. And they learned much. Of the passage they believed they had found out to the surface, she knew little. But she showed them, with doubt in her face, that there was almost hopeless struggle along that path to the freedom above. Sadly she touched Jerry's injured arm, and she shook her head in dejection. The arm had had a bad wrench, Jerry found. No fracture, but the muscles and ligaments had been painfully torn. But Jerry set his teeth firm at the thought of a possible escape. * * * * * Once, peering along the dark passage that led to the room where the others had been seen, the men noticed the deep bows that unfailingly marked the entrance of Marahna. They questioned her and learned that here was royalty among the people of the moon. This, as they considered the proud poise of her head and her whole attitude of unassuming superiority was not entirely surprising. But they marveled the more at the truth that she finally made plain to them. Marahna, she told them, as plainly as if she were speaking in their own tongue, Marahna was chosen for death. And her white face was pitiful and her eyes full of horror as she enacted for them the slow march she must take up the long golden slope and into the horror that waited. "A sacrifice to that god!" Jerry spoke with dismay. "No, no!" But the face of the Princess Marahna of the moon people was unutterably sad with unspoken thoughts as she touched her breast with one slender finger, then indicated the outer room and showed there were two there beside herself who were to go. "Help us to get out," Jerry begged, and with fierce eagerness he showed them going through the passage to the outside. "We will come back, and we will find some way to end all this damnable thing."