"The Fifth Ace" by Douglas Grant is a novel written in the early 20th century. This engaging story revolves around Kearn Thode, a young petroleum engineer who arrives in the booming oil town of Limasito, Mexico. The narrative introduces a range of characters including Gentleman Geoff's spirited daughter, Billie, and the mysterious legend of the Lost Souls' Pool, hinting at themes of love, duty, and danger within the rich backdrop of a developing frontier town. At the start of the story, Kearn Thode rides into Limasito and quickly discovers its charm as a thriving community bustling with potential. His encounter with Billie—a confident, captivating girl untouched by the roughness of her environment—leads him into the tension-filled world of gambling and local lore. The narrative sets up conflicts, hinting at a deeper connection between the characters and an emerging threat from the legendary El Negrito. As Kearn navigates this new landscape, the mysterious lore of the Lost Souls' Pool intertwines with his interactions, foreshadowing the complexities and trials he is bound to face in this intriguing locale. (This is an automatically generated summary.)