| CHAPTER | PAGE |
| I. | THE END OF THE UNDERGROUND RIVER | [ 1] |
| II. | SKY HIGH | [ 11] |
| III. | THE RETURN TO THE LAND OF THE INCAS | [ 24] |
| IV. | THE RIVALRY OF THE AIRMEN | [ 32] |
| V. | IN QUEST OF THE HIDDEN TREASURE | [ 43] |
| VI. | THE CROWNING MISFORTUNE | [ 55] |
| VII. | IN THE TIGER’S LAIR | [ 66] |
| VIII. | THE INCA’S THREAT | [ 80] |
| IX. | SONCCO’S SHREWDNESS | [ 92] |
| X. | THE PRISONERS CAPTURE THE KING | [ 105] |
| XI. | THE COUNSEL OF THE WISE MEN | [ 116] |
| XII. | THE VILLAINY OF VILLAC UMU | [ 128] |
| XIII. | STANLEY’S PLAN | [ 140] |
| XIV. | SONCCO’S AID TO THE PLOTTERS | [ 151] |
| XV. | THE TERROR OF DARKNESS AT MIDDAY | [ 165] |
| XVI. | THE COMING OF THE TIGERS | [ 180] |
| XVII. | ANIMALS OF A BYGONE AGE | [ 193] |
| XVIII. | THE MAN IN THE CRATER | [ 205] |
| XIX. | THE BREACH IN THE MOUNTAIN IS CLOSED | [ 221] |
| XX. | THE KING IS CROWNED | [ 233] |