Immediately after breakfast, and during Taggert’s absence, they were visited by the emperor. Fearing to hear of his own clandestine call upon the princess, Robert prepared himself for the worst. But the emperor apparently was ignorant of the matter, for he merely inquired regarding their welfare and begged them to accept an invitation to attend a meeting of his learned men to discuss life on the two planets; he seemed much pleased over their progress in the Martian tongue. While he was there Taggert returned with the articles mentioned that morning. Those he made no effort to conceal. After a few words with him the emperor bid them adieu. “When is this meeting he’s spouting about?” Taggert inquired anxiously. “Tomorrow evening,” said Robert. “Too bad we must miss it. Professor Palmer could gather a great deal of interesting data regarding Mars from those men.” “He would if those pirates would give him a chance to ask a question,” said Taggert. “But the chances are that they’d keep him dizzy satisfying their own curiosity.” “Never mind, boys. I’ll no doubt have other favorable opportunities to gather all the data I want from our polar friends when we reach their country. What is more important now is the condition of the _Sphere_. You haven’t told us what shape you found things in, Taggert.” “Oh, everything looks all right, thank goodness,” answered Taggert. “I took a peep into the petrol tanks, too, and turned the gyrostats over a few revolutions. Saw a couple of these runts hanging around, but I guess we’ll be able to pull off our party O. K. I tried to act as if there was something out of order for their benefit in case they were spies.” “Good idea. That will offer a plausible reason for my going over this afternoon,” said Robert. Having laid all their plans carefully, Robert and Taggert visited the _Sphere_ late that afternoon, and together they tinkered and tested for the benefit of the two or three Martians who were ever about, as well as for their own benefit to see that everything was in working condition. Fortunately everything was in the same shape as when they had left it. About sunset Taggert left, taking word that Robert was engrossed in making some delicate repairs and would not return for dinner. 15 As the twilight rapidly faded Robert observed with uneasiness that three Martians remained within the building where the _Sphere_ was placed. His suspicion that they were spies was strengthened when one of them engaged him in conversation and inquired whether he might accompany him within the _Sphere_ to learn something of its intricacies. The note of insistence in the Martian’s voice convinced Robert that a refusal would be useless. He granted the request gracefully, biding his time until he felt sure the princess would be ready. Then it would be up to him to get rid of the spies in some manner. Just how he was to accomplish this he did not yet know.