Though Cavendia has passed into an industrial age of steam power and metallic cartridges, none have ever returned to the Black Continent of Tanzia, where life began, and where the monsters of the ancient world still roam. Now, after centuries of isolation, Cavendia is sending the mysterious and dangerous Ambassador Chadwick Yates, along with decorated soldier Thurston Sharp, on an expedition to meet the sentient races of Tanzia (Gremlins, Faeries, the frog-like Anurans, the revered Altaica, and the Nadhili tribes of men). What cultures have these strange races developed, and how have they survived in the land ever haunted by the Servants of Maraa the Terrible, the sorcerer who once enslaved all life?
Capable of any adaptation, Yates and Sharp must go beyond the language of diplomacy and use the language of action which all free beings understand. They must earn the trust of alien civilizations and unravel the wonders of the ancient world. Fighting alongside the native peoples and with powerful firearms and more than a few technological gadgets, the two gentlemen explorers soon find themselves set against a plot that would topple more than just Tanzia.