"Tens of thousands of green men they have prisoned here like us, for the sole purpose of supplying them with blood. For the Ralas live on this blood alone, changing it chemically to fit their own bodies and then taking it into their bodies. It eliminates all necessity for food here for them. Every few days they drain blood from us, and since we are well fed and cared for to keep us good blood-producers, we will be here for a long time before we die." "But haven't you made any attempt to get out of here--to escape?" Norman asked. Sarja smiled. "Who could escape the city of the Ralas? In all recorded history it has never been done, for even if by some miracle you got a flying-boat, the opening of the water-tunnel that leads outward is guarded always." "Guards or no guards, we're going to try it and not sit here to furnish blood for the Ralas," Norman declared. "Are you willing to help, to try to get to Fellows and your city?" The green man considered. "It is hopeless," he said, "but as well to die beneath the force-shells of the Ralas as live out a lifetime here. Yes, I will help, though I cannot see how you expect to escape even from this room." "I think we can manage that," Norman told him. "But first--not a word to these others. We can't hope to escape with them all, and there is no knowing what one might not betray us to the frog-men." He went on then to outline to the other two the idea that had come to him. Both exclaimed at the simpleness of the idea, though Sarja remained somewhat doubtful. While Hackett slept, weak still from his loss of blood, Norman had the green man scratch on the metal floor as well as possible a crude map of the satellite's surface, and found that the city, where Fellows was, seemed some hundreds of miles back from the sea. * * * * * While they talked, the sunlight, apparently sourceless, that came through the heavily barred windows of the room faded rapidly, and dusk settled over the great amphibian city beneath the giant dome, kept from total darkness by a silvery pervading light that Norman reflected must be the light from Earth's great sphere. With the dusk's coming the activities in the frog-city lessened greatly. With dusk, too, frog-guards entered the room bearing long metal troughs filled with a red jellylike substance, that they placed on racks along the wall. As the guards withdrew the men in the room rushed toward the troughs, elbowing each other aside and striking each other to scoop up and eat as much of the red jelly as possible. It was for all the world like the feeding of farm-animals, and Hackett and Norman so sickened at the sight that they had no heart to try the food. Sarja, though, had no such scruples and seemed to make a hearty meal at one of the troughs.