The Emperor gave long consideration to the means at his command for effecting their rescue, but none of them appeared practicable. One thing was certain. If an attack were made upon his really impregnable castle the Sultan would carry out his threat. Then again of what use would it be to capture the castle, even if it were possible? They could not catch the Sultan and bring him to account so long as they could not cut off his escape by sea. As for negotiation, the Emperor gave it no thought. He was certain that the Sultan would not make a second offer; and even if he found that the Emperor was willing to listen, he felt sure that he not only would repeat the old demands but probably would add new and not less ignominious ones. From every point of view the deed was almost superhuman. The castle could be approached only by land, over a narrow causeway, which was in plain sight and could be easily defended. But even if they crossed it without resistance, they would come to portcullises which could be easily lowered so as to cut them off and ensure their destruction. Seawards a large inclosure was filled with most trustworthy guards—a number of huge and powerful lions, tigers, and panthers, whose loud roars were terrible enough to prevent any one from attempting to scale the wall on that side. But even supposing a knight were found ready to attempt this rash exploit, what could be accomplished? Could he rescue the boys from the Sultan and escape with them past the castle garrison? And if he failed what would become of the Emperor’s promise? Would he have risked his life for them as he agreed? He would have done no more than any other might have done and the faithless Turk would have laughed at him for his pains. Frederick’s honor had thus far been unquestioned. His word was of more worth than gold. He could not escape the conclusion that to uphold his honor to the last he must undertake the deed alone. This thought flashed through his mind like the lightning. A knight in every sense of the word, as his whole life had shown, Frederick had all the virtues of true knighthood in their highest development. In his time knighthood was not satisfied with ordinary dangers. It sought for daring exploits, and purposely invited and magnified them that victory might be all the more glorious. It was regarded as a misfortune that the world no longer swarmed with dragons and serpents, with which, according to the legends, the heroes of the olden time contended. Giants and goblins had also disappeared, and the knightly heroes therefore eagerly seized the opportunity to encounter dangers in the Orient they had never faced before, and to overcome them and thereby display their knighthood as well as their religious enthusiasm.