Diamond

Along the Zambesi river, in the heart of the damp and dark tropical forest, the geologist Margaret Tracy believes she can discover where the enormous diamond was found. 

 But when the head of a lion, sculpted on a rock, terrifies the bearers, and from under the climbing plants a tombstone scratched in unknown characters emerges, Meg should accept the idea that her degree and the experience of Jeff are not enough to carry out the mission. 

Which secrets are hidden by the dreadfully disfigured primitive men that live in that area?  And why a patrol of German explorers reported the presence of that people to the generals of the third Reich? 

Professor Pitkoski, an archeologist, will find the key to join pieces than seem to be part of different puzzles.

Among the ruins of a lost town, stalked by horrifying presences and hunted by the cultist of the science born in the nazi lager, the expedition is trapped in a deadly grip.

The Maya secret

In Egypt to search the legendary beacon at Alexandria, the archaeologist Simon Parker receives an offer that would solve a lot of his economical troubles: a small change in the program of the expedition should be enough to comply with the request of the Magnusson International, but what is hidden behind the apparent innocence of the proposal?

The project of the Magnusson is top secret: the new energy source discovered in one of its laboratories will replace oil and nuclear. For Thomas Crowton, president of the company, the monopoly of the energy market will be the tool to reach absolute power.

While a series of inexplicable railroad disasters throw the United States in the chaos, Crowton manoeuvres for his triumph.  Meanwhile, in Guatemala, where he went to accomplish his mission, Simon have became a target. What did he discover? And who wants he dead?  The mysterious inscription purloined from the big pyramid of Tikal attracted Simon in a maze in which every step could be the last.

Where the alliances last less than a handshake and a clic can move enormous amount of money, how to find a solution if every clue leads to a blind alley and Mac, sly computer genius, works incessantly to confuse the tracks?

Incunabulum

Umbria, Italy, around 1300 a.C.  In a dark century, a monk whose life was worth less than the rope that rounds his hips, sees something that he should ignore and hears words that none should have heard.

New York, 2001 d. C.  At Christie's it's knocked a precious incunabulum. For Donna Carson, rich and fascinating collector that win it, no place is anymore secure. 

Which secret is hidden in the ancient miniatures? And why someone can kill to get the volume?

Together with professor Forrest, who estimated the book, Donna is involved in a treasure hunt whose light track is traced in the sharp clues of slick amanuenses and in which it's not sure that to arrive first is enough to be save.

Aspides

What is scratched on the little wood that Maria hung to the neck of Jesus a little after his birth? 

 Purloined the pendant from the treasure of Costantino, the empress Galla Placidia would know how to use it's mysterious power to restore the ancient splendors of the decadent western roman empire, but the disappearing of the relic risk to vanish her plan. 

 Who profaned the secret niche of the mausoleum? And how to get back the precious object? 

 Involved in a game he doesn't know, among politicians, soldiers, bureaucrats and ecclesiastical in struggle for the power, the young Aspar can trust nobody but himself to exit alive from the snake-pit in which he fell.