The Secret of Boca Verde (El secreto de Boca Verde)

When a Spanish documentary filmmaker agrees to lead the rescue of a group of young people who have disappeared in the Amazon, he is drawn into a deadly race against mercenaries and drug traffickers for a treasure hidden beneath a lost city. A high-octane adventure novel by genre master Alberto Caliani.

David Beltrán is a journalist and documentary filmmaker specializing in exploration. Alongside his inseparable cameraman, Royi Durán, he travels to the most remote places on Earth in search of extreme stories. During a shoot in Peru, they accidentally discover an impossible place: a hidden natural entrance along a tributary of the Unu Rono River, concealed behind a curtain of vegetation so dense it is invisible from the water. Beyond it lies a crystal-clear stream and a green path leading deep into the jungle. David names the passage Boca Verde. Unknowingly, they have found a natural gateway that has protected what lies beyond for centuries.

David shares the discovery with Gérard LeVu, a friend with whom he often discusses exploration. Gérard, son of French magnate Louis LeVu, is obsessed with an ancient mystery: he believes that the explorer Francisco de Orellana did not die as the official version claims, but instead founded a secret colony deep in the Amazon, deliberately erased from historical records. Based on unpublished documents, Gérard is convinced that this city—Nuevo Trujillo—lies beyond Boca Verde. Determined to prove it, he secretly organizes an expedition with several friends.

Shortly afterward, in the Brazilian Amazon, an Indigenous boy finds a canoe drifting along the Purús River. Inside lies the lifeless body of Antoine Villeneuve, one of the expedition members, shot dead. In his hands he holds a perfectly preserved ancient sword. Alongside the body are a diary and a camera. The material confirms that the group reached Boca Verde and reveals that Gérard and the other members are still alive, detained by an Indigenous community that protects the enclave and does not allow anyone to leave after discovering it.

Louis LeVu sends a representative to Madrid to contact David directly: only he knows how to access Boca Verde. He offers him the chance to lead a fully funded rescue mission, with complete freedom to document everything. David accepts, driven both by personal loyalty and by the historical magnitude of what might lie there.

The mission is organized with heavy security. Louis LeVu finances an armed team of mercenaries to protect the civilians during the operation in a region dominated by drug traffickers. The expedition travels up the Unu Rono in a perilous journey through dense jungle, narco-controlled territories, and areas virtually cut off from the world.

Upon locating Boca Verde and advancing along the hidden stream, they find Gérard. He is not chained or tortured, but kept under constant watch. The Indigenous community guards a secret buried for centuries. Beyond the path stands an enormous structure covered in vegetation—an artificial mountain built to conceal and protect the intact remains of Nuevo Trujillo, a 16th-century colony established with the help of an advanced Indigenous civilization that has preserved the site generation after generation.

The discovery is real. Monumental. And extremely dangerous.

It soon becomes clear that the rescue was never the sole objective. Charles Forest, the mission’s operational chief, uses the armed force financed by the LeVu group to execute his own plan: to seize the enclave and exploit its historical and strategic value. Gérard was to be rescued, yes—but Forest intends to turn the operation into a territorial occupation and eliminate anyone who stands in his way. The presence of armed men and aircraft in the jungle alerts local drug traffickers, who interpret the incursion as an invasion of their river routes. Violence erupts: shootouts, internal betrayals, and clashes with the narcos plunge the expedition into chaos. Several people die, including Forest himself, shot during the conflict.

In that green hell, Gérard loses one of his closest friends and understands the true cost of his obsession. David, who had dreamed of documenting the most important discovery of his career, realizes that making it public would mean the immediate destruction of the enclave by governments, corporations, and looters.

When the situation becomes untenable, the survivors break through the encirclement and reach a seaplane used for logistical support. Under enemy fire, they take off from the river in a desperate maneuver. Mid-ascent, one of the mercenaries manages to cling to the aircraft and attempts to board, triggering one final brutal confrontation before falling into the void.

From the air, they gaze one last time at the endless jungle and the green mountain hiding the lost city. They possess enough evidence to rewrite history.

But they make the hardest decision of all: the world is not ready to know about Nuevo Trujillo. If revealed, the enclave will be destroyed.

The rescue will be made public. The discovery will not.

Boca Verde merges once again with the jungle. The vanished city remains intact, outside history and off the map. And David returns home knowing he has held the greatest discovery of his time in his hands… and that his bravest act was burying it once more.

RELEVANT INFORMATION: Alberto Caliani is a Spanish writer and screenwriter. After an early career as a comic book artist and contributor to specialized publications, he devoted himself fully to literature, building a diverse body of work spanning adventure novels, historical thrillers, and horror.

Caliani has received the Premio Pandemia (2013), the double Premios Hislibris (2021) for Best Historical Novel and Best Spanish Author, and the Premio José Rasero Balón for Best Crime Novel. His works have been widely praised by both critics and readers.

El secreto de Boca Verde is an adventure thriller that masterfully blends action, mystery, and historical investigation in the spirit of Indiana Jones. The story begins as a rescue mission and transforms into a race against time, featuring elements tailor-made for the big screen: a hidden treasure, mercenaries, betrayals, and a secret city.

The novel’s pace is truly relentless, with a clear plot, powerful twists, and a hero pushed to his limits. It has blockbuster DNA and enormous audiovisual potential as a high-impact adventure film.

AUDIOVISUAL POTENTIAL: TV Series, Miniseries, Feature Film, TV Movie.

AVAILABLE LANGUAGES: Spanish.