The ongoing adventures of the courageous Bomba the Jungle Boy! In Bomba, the Jungle Boy on the Underground River, Sobrinini, the snake woman that Bomba rescued from Snake Island, is also undergoing treatment. During her more lucid moments, she has told Bomba of a chest that she buried in the banks of an underground river. It contains documents and records related to Bombas parents. Sobrininis disordered mind prevents her from sharing the document information herself, but she is able to give Bomba crude directions to the chest. Bomba and Sobrinini, along with the natives Gibo and Neram, are now on their way to find the Underground River and retrieve the chest. Underground River is filled with adventures that challenge Bombas great strength and fortitude, making for another exciting volume in the Bomba series.