Another litter was passing along the cross street just ahead of them. This litter went in evident haste, with lackeys swinging whips to clear the path and the passenger bending forward to urge his bearers to greater haste. The man who rode in the litter was Xylon! The four outlaws stared at each other in grim and ominous surprise. There had been no doubt of the identity of the man who had just passed within a few yards of them. "But what does _that_ mean?" Larry gasped. "It means that I have been a fool!" Pyatt snarled. "Xylon is evidently no outlaw who came to the caverns to seek shelter, but a spy sent out by the Lords of Gral-Thala. Now I understand the reason for that revolt among the Insect-men! He must have stirred it up in an attempt to kidnap Diana here because of her hold over those simple creatures. Now the location of the Lost Caverns is at last known to the tyrants, and there will be an attack in force." "And Xylon knows that we are here in Pandonaria!" Diana exclaimed. "Which means that all our lives hang by a thread no heavier than a woman's hair! We must get under cover at once! Then we will send word back to the Caverns by secret radio, that they may prepare for an assault. After that we will plan an attempt on the radium salts." The outlaws of the Lost Caverns had certain confederates within the city, and they now took refuge in the house of a small merchant who was a distant cousin of Pyatt. Larry watched as Pyatt and the merchant crouched over the sending set concealed in a small closet built in the thickness of one of the walls, the arkon-bulbs flashing as they sent the warning to Chotan to be spread to the other caverns. At last Pyatt straightened up. "At least that is done," he said. "Now we will wait two hours, which will be the time of the Third Meal. There will be few people on the streets, and the warehouse guards will be drowsy, and we will have our best chance." * * * * * Pyatt and Colton had gone somewhere else in the house, and Larry sat with Diana in a small room whose windows looked out on the green fields beyond the city. The girl had loosened her blue veil so that it hung in soft folds about her chin. "This is the first time in my life I have been anywhere but in the Caverns and on the waste-land," she said moodily. "This valley of Gral-Thala is a pleasant place." "You would like Earth even better." "I suppose I would. Will you take me back to that Earth of yours when you return, Larry?" "Not until the Gray Death is overcome! I would not want to take any chance of it striking you down." "Do you love me, Larry?" she asked, without either coquetry or embarrassment. "I guess I do. Of course, we've only known each other for a few hours--but I guess I do." "I am glad," she said simply.