“Jump in,” said the captain, as he set the example. Dan threw in the clutch and the car whirled out of the gate.

While uncle and nephew are speeding to respond to that call for help from faraway Egypt, it may be well, for the benefit of those who have not read the preceding volumes of this series, to tell who Don Sturdy was and what had been his adventures up to the time this story opens.

Don was a lad of fourteen, unusually tall and muscular for his age, with brown hair and eyes and a fair complexion. He had been born and brought up in Hillville, a thriving town in an Eastern state, about fifty miles from New York. The Sturdy house was of stone, as were the barn, garage and other outbuildings, surrounded by several acres of ground set out with large trees.

Some time before the beginning of the events here narrated, Don’s father, Richard Sturdy, a great traveler, had set out on an exploring expedition, accompanied by his wife, Alice, and by his daughter, Ruth, who was about two years younger than Don. No word came from them, nor did the ship Mercury on which they had embarked reach port, and with the passage of time it began to be feared that the Mercury had gone down with all on board while rounding Cape Horn. The blow was a terrible one to Don, who dearly loved his parents and younger sister, and drove him nearly frantic with grief.

During his parents’ absence, Don had been left in the care of his uncle on his father’s side, Captain Frank Sturdy, his official guardian, a big game hunter of great repute, whose business of gathering animals dead and alive for museums and menageries had taken him at times all over the world. He was a big man of iron nerve, sinewy, with black hair and eyes. He was a dead shot, and his instructions had made Don also a marksman only second to himself.

Don was also under the general oversight of Professor Amos Regor Bruce, his uncle on his mother’s side, and an eminent scientist and member of many learned societies. He also had traveled extensively in the interest of museums, for whom he gathered rare archæological specimens.

To divert Don’s mind from dwelling on his supposed loss, his uncles, both of whom were bachelors, took him with them on a trip to the Sahara Desert. There one adventure trod quickly on the heels of another. Don rescued a boy of about his own size, Teddy Allison, from the attack of thievish Arabs. It developed that Teddy’s father had been captured and carried into slavery. The sympathies of Don and his uncles were enlisted by the boy’s plight, and they organized an auto expedition into the desert to find Mr. Allison and incidentally to discover, if they could, the City of Brass and the Cave of Emeralds. What difficulties they had to surmount; the encounters they had with bandits; the thrilling circumstances attending the rescue of Mr. Allison and their finding of the emeralds are told in the first volume of this series, entitled: “Don Sturdy on the Desert of Mystery; or, Autoing in the Land of the Caravans.”

Don’s astonishment and delight may be imagined when he learned from Mr. Allison that, though the Mercury had indeed been shipwrecked, a number of passengers on the ill-fated ship had been picked up by a sailing vessel and carried to Brazil. Teddy’s father had heard the story from others of the rescued party, a scientist and a sailor, who were presumably somewhere in Brazil, though he did not know their exact whereabouts. Don’s hopes that his parents and sister might have been among the survivors were revived, and he and his uncles determined to go to that great South American country, a project rendered the easier by the fact that the captain had a contract to capture big snakes and the professor wished to go to the same region to search for rare drugs.

Before long their expedition was organized and they had plunged into the wilds of Brazil. Here they had the most exciting adventures with anacondas, boa constrictors, alligators and jaguars, and were many times in peril of their lives.

How they captured the hideous monsters of the jungle; how they followed up traces of Don’s parents and sister and finally found Ruth in a hospital and brought her back to America; how they were baffled by the perplexing mystery that still clung about the movements of Don’s father and mother, are fully narrated in the second volume of this series, entitled: “Don Sturdy with the Big Snake Hunters; or, Lost in the Jungles of the Amazon.”