It was only an instant that they hesitated there, yet it appeared an eternity of indecision, then nearer footsteps sounded, coming down that hall. No more wavering of the scales! Ryder turned to the door at his left, at the very end of the wall beyond which came that far stamping, and wrenched it open, closing it swiftly behind him. He saw a light now, a mild, yellow ray through an opened door ahead that vaguely illumined the strange old vehicles of the palace, and the stables were beyond. Some one else was beyond, too, in the stables, for that very instant he saw a black horse backed restively into sight, its tossing head evading the hands that were trying to bridle it. "The Fortieth Door!" said Ryder to himself with an involuntary thrust of humor. The door of the horse! The door of forbidden daring! He knew now the vague associations that had stirred in him as he had stared blindly about that place of doors.... But he had opened so many forbidden doors of late that this last was welcome as the supreme test. And nothing in the world could have been more welcome than a horse--a horse with a way out behind it! "Stay back," he said under his breath to Aimée, and clasping his bit of iron he moved toward the door. He could see the attendant now, who was finishing his bridling, and it was Yussuf, the eunuch, so busy gentling and soothing the horse that he cast only one glance in the direction of the sounds he heard and that one glance misled him in its glimpse of the general's cloak. "By your favor--but an instant," he called out, "and he is ready--" "Stand aside," said Ryder very clearly, emerging from the shadows at the horse's heels. "Out of the way with you. The horse is for me." A moment Yussuf gaped. Then he dropped the bridle and his hand went swiftly to the knife hilt in his belt. "Fool!" said Ryder contemptuously. "Would you tempt fate? Do you think I am such that your knife could harm me? Must I prove to you again that walls are nothings--that I but let myself be taken to prove my powers?" Ethiopians are superstitious. And Yussuf knew that his brick and mortar had been strong.... Yet they have great trust in a crooked, short-bladed knife, and Yussuf did not relax his hold upon his and for all that Ryder could See there was no hesitation in the grinning ferocity of his black face. Yet his spring was an instant delayed and in that instant Ryder spoke again. "Look, now at the wall behind you," he said quickly. Yussuf looked. And as he turned his bullet head Ryder jumped close and brought his iron down upon it with a sickening force he thought scarcely short of murder. To his amazement the black did not fall, but staggered only, and Ryder had need to send the knife spinning from his grasp and strike again before the eunuch's knees sagged and his huge bulk sank at Ryder's feet.