The sentinels were tolerably sober, for they were not to get their full share of the flood of wine that was flowing till their guard was relieved. But they could hardly be blamed for obeying Zeno's imperative command. It was not likely that a guardsman of their troop who wished to slip out of barracks for a night's amusement would dress himself in full uniform and come galloping and shouting to the gate, nor that any trooper would dare to pretend that he rode on the Emperor's business if it were not true. The two sentinels therefore did not hesitate, but set their long cavalry lances upright against the walls on either side, took down the bar, and laid hold of the ponderous gates, each man taking one and throwing himself backwards with all his weight to move it. When once started, the doors swung slowly but easily backwards. Zeno sat motionless in the saddle, ready to dash forward as soon as there was room for him to pass. He had halted just far enough away to allow the doors to swing clear of his horse's head as they were pulled inward. It was an anxious moment. A second more and there would be space between the yawning gates. But that second had not yet passed when a tall officer in scarlet rushed shouting from the open door of the guard-house, and seized Zeno's bridle. 'Stop him!' yelled the lieutenant. 'Shut the gates!' The two soldiers did their best to obey instantly, but the leaves of the gate were of cypress wood four inches thick, and covered with bronze, and were swinging back faster now under the impulse they had received. It was impossible to check them suddenly, and the order was hardly spoken when Zeno saw that there was room to ride through. He would have given his fortune for a pair of Arab spurs at that moment, but he struck the corners of his heels at the horse's sides with all his might, and almost lifted him by the bridle at the same time. The big Tunisian answered the call upon his strength better than the rider had dared to hope; he gathered himself and lifted his forequarters, shaking his head savagely to get rid of the hands that grasped the off rein close to the bit, and then he dashed forwards, straight between the doors, throwing the officer to the ground and dragging him violently away in the powerful stride of his heavy gallop. Seeing what had happened the sentinels started in pursuit at full speed, following the sound of the charger's shoes on the cobble-stones rather than anything they could see, for it was as dark as pitch outside.