The giant's answer came back sluggishly. "_I can ... understand._" "That is well. Then listen to me, and mark well my words. I am Master here. Do you acknowledge that?" The creature stirred restlessly. "Master? I accept no Master. I am Master of mine own will." Grossman pressed the grip of his Haemholtz. A flash of livid lightning seared the subterranean chamber. Grossman challenged, "You defy the Master of the fire-that-bites?" The giant cringed against the farthest wall. "Nay!" he conceded. "You are Master. I am your servant." "It is well you understand. For there is work to be done. When it is accomplished, then you will be freed. Hear now, huge one, what is expected of you...." VII "Manacles!" repeated Rocky Russell, "Manacles twenty feet in circumference! But that--that's impossible! Handcuffs for a normal six-foot man measure about six _inches_ in circumference. Twenty foot manacles would be used on someone _two hundred and forty feet tall_!" "Always assuming of course," Lynn pointed out, "that these gyves are to be used on a _man_. Which isn't very likely. Much more possible that they were constructed for some beast ... some tremendous animal--" "True," admitted Rocky. "But even so--imagine the size of that animal! Well, that settles it. Bud, I want you to take Miss Graham back to the fort immediately." "And you?" "I'm going to follow that roller." "But there may be danger--" "There undoubtedly _is_ danger," replied Rocky grimly, "directed at the Patrol ... perhaps the whole of Titan. Those manacles are somehow associated with Grossman's secret. I've got to learn how. You can help best by racing back to Beausejour and warning Colonel Graham to be on guard against any eventuality. Keep your portable vocoder tuned to our private wave-length. If and when I learn anything important I'll send it on to you. O.Q.?" Bud shrugged helplessly. "You're the boss. But I'd rather stay here with you and--" "Get going! Oh--when you reach the Base, take off the lid. Tell Colonel Graham who we are." "And if it's not too much trouble," interrupted Lynn Graham, "would you mind telling me _now_?" Rocky grinned at her, for the last time using Dr. Roswell's high whine, "Oh, mercy, Miss Graham, you mustn't be impatient. Ambrose will tell you as you ride." "_Ambrose!_" fumed Bud. "Ambrose be damned--!" But he was talking to empty space. Rocky had already disappeared down the avenue after the gyve-laden roller. Fortunately the roller, groaning under its ponderous burden, was not moving very fast. Rocky, though on foot, was able to keep it within sight without too obviously appearing to be following it. In the character of Dr. Rockingham Roswell, already known and amusing to the Titanians, he dawdled through the city five hundred yards or so in the wake of the burdened vehicle.