There was a sudden soundless flash. From across the room a beam of violet flame darted at us. It struck just between Maida and Wolfgar, as he rose from his knee. Both of them involuntarily stepped backward, apart from each other. And between them, breast high, the flame hung level across the room. Maida was on one side of it; all the rest of us, on the other. I turned. At the door, Argo had appeared. From a black object in his hand, the beam was streaming. He rested the black thing on a wall ledge so that the beam hung level. "Stand where you are, all of you." He started toward Maida, behind the beam from the rest of us. Georg made as though to leap forward, but Wolfgar restrained him. "Wait! You don't understand--that's death!" I saw now that the violet light had encircled us. Only Maida and Argo were outside it. He was approaching her, with a cylinder in his hand. The ray from it struck her without power of movement or speech. Her eyes, terrified, turned to us. Again Georg would have leaped, but Wolfgar shouted, "Wait! That's death! Don't you understand?" Argo was leering. "Death? Yes! If you touch that violet light! Death, of course. But you won't touch it! You will stand and watch--stand silently for you know that if you shout, the vibrations will bring the beam upon you. You won't move--you'll stand and watch me kill your Princess Maida--not quickly--she is too beautiful for that. You, Georg Brende--you, Wolfgar, traitor from Mars. You shall see your Princess Maida die--this would-be traitoress to my Master Tarrano!" With all the strength of his puny body Wolfgar flung Georg backward--safely away from the deadly violet beam. And then, without warning, without a cry which would endanger us, the little Mars man sprang headlong, into and through the violet beam of death. CHAPTER XVIII _Passing of a Friend_ Wolfgar was not dead; but when we picked him up it was obvious that he was dying. The violet beam vanished as his body struck it--vanished with a hiss and splutter, and a puff of sulphuric smoke that mingled with the smell of burning garments and flesh. Georg and I leaped forward. Argo was standing transfixed by surprise at what Wolfgar had done; and as the beam died, Georg was upon him. "One moment!" The quiet, commanding voice of Tarrano. He must have come quickly, when informed by the finders of Argo's treachery. Yet he stood now at the arcade entrance, drawn to his full height, frowning with lowered brows, but wholly without appearance of haste. "One moment--stand aside, all of you." Argo cowered. The rest of us moved aside. Elza came toward me, and I put my arm around her. Poor little Elza! She was shivering with fright. Tarrano seemed not to need information as to what had transpired. His eyes, roving over us, saw the lifeless, seared body of Wolfgar lying on the floor. "Too bad," he said. Then his gaze swung to Argo. "Master----" "Silence!"