carried away by the exciting spectacle they had just witnessed, were standing at their full height in the long grass, fully exposed from their waists upward, and with the light glancing brightly from the polished silver-like barrels of their rifles. A moment's pause was sufficient for the unicorn; some subtle instinct doubtless taught him that in the strange beings who had thus unexpectedly revealed themselves he beheld enemies more dangerous than the most deadly of his four-footed foes; and, wheeling quickly about, he uttered a curious barking kind of neigh and dashed off at a headlong gallop in the direction already taken by the rest of his companions. "Good Heavens, we have lost them!" groaned the professor in a perfect agony of despair. "Yes," assented the baronet, who next turned to his more distant companions and hailed them with: "We have had our trouble for nothing, after all. The best thing we can now do is to make our way back to the ship with all speed, when we can renew the pursuit, unless, as seems only too probable, we are about to have our hands full with the coming storm. We have not a moment to lose, I should say; so I would suggest that each of us put his best foot foremost." "Ay, ay," replied Mildmay, "crowd sail we must; for, unless I am greatly mistaken, we are about to have a regular tornado." "A tornado!" gasped the professor. "Run--run for your lives; I verily believe _I forgot to moor the ship_!" Forgot to moor the ship! Could such fatal carelessness be possible? If so, they must indeed run for their lives; for should the storm burst before they reached the ship she would be whirled away over the plain like an empty bladder before the blast, to what distance and with what results it was difficult just then to foreshadow; but among the possibilities which instantly presented themselves to the mind was that of death to the two inmates of the ship, irreparable damage to the craft herself, and four persons left to shift for themselves in the very centre of Africa, with nothing but the clothes they wore, the rifles they carried, and about a dozen rounds of ammunition apiece. The prospect was appalling enough to send a momentary spasm of horror thrilling through the stoutest heart there, but it also at the same time endowed them with a temporary access of almost supernatural energy; and the four men at once started for the ship at a speed which, even at the moment and to themselves, seemed incredible.