When two boys stumble upon a body washed ashore, it shatters the tranquility of the idyllic capital city on a paradise island. Professor Valeriane Ducasse unveils a groundbreaking discovery from her extensive research on the island, leading her into a web of criminal intrigue. Investigating a crime is no small feat. Fabio Grignon learns this firsthand on a tropical island steeped in myths, folklore, and a rich cultural tapestry. Tasked with solving a crime, the detective must navigate the island's intricate cultural nuances while collecting evidence and questioning suspects. The island's unique environment and culture become integral to the narrative, offering a distinctive and exotic setting for the investigation.

"The Lost World of Mu" delves into themes like evolution, adaptation, and the intricate relationship between humans and the natural world.