Out by the gate in the dazzling sunshine sat Ibrahim upon his tall camel, the headgear for the present carefully arranged so as to make a brave show, and the seven mounted guards waiting for the Hakim's learned slave, who bore the reputation now of being deeply versed in magic to such an extent that he could call down lightning from the skies and make it do his will. A horror this to the ignorant Soudanese, and something to make them tremble, but no exaggeration. For to us of this century who can send our messages to the other side of the earth and receive back answers in a few hours; talk with friends at a distance, and recognise their voices; receive their speeches, their songs, or the melodies of instruments impressed on wax, to reproduce whenever we please; these and scores of other such scientific marvels are but everyday matters of business, common trifles, though they dwarf many of the magic legends of the Arabian Nights. Consequently the Hakim's black slave was greeted with profound reverence by the Emir's bodyguard as he rode out, stern and thoughtful, upon the mission which he felt to be the greatest of his life, and barely noted that his beautiful horse ambled along as if proud of this rider in the flowing white robes, and whose richly ornamented sword beat softly upon its flank. Frank gave one glance back, however, to see that the Sheikh's camel was pacing along a few yards behind, the thick, long, scarlet horsetail plume waving beneath the ungainly animal's neck, while the seven horsemen rode, fiercely important, a few yards behind the Sheikh, each with his round bossed target and gleaming spears. For one moment Frank thought of self, and how strange it all was that he, the young Englishman, accustomed to London and its ways, the student of chemistry, full of experimental lore, should be riding there in disguise, the Hakim's slave and assistant--the favourite of a powerful Baggara Emir and his son--riding through the teeming crowds of that hive of horror, bloodshed, and misery, and those familiar with his appearance making way at once. It was all like a dream for a few moments, or as if he were reading with strong imagination some romantic work descriptive of a scene in the south and east. Then it was all real again--horribly real--and he rode gently on, thinking of the part he had to play, and wondering wildly whether he would have the nerve to go through all he had mentally planned, and whether if he were successful in getting alone with his brother, Harry would bear the announcement of there being help at hand. "It all depends on me," thought the adventurer, as he rode on, stern, and gazing straight before him, hardly conscious of the crowd through which he passed, or the whispers of the people who recognised the Hakim's follower; for he was busy working out his plans and picturing the scene in which he was to play that critical part.