Every hundred years, four kids from four cities must save the world . Rome, December 29. A mix-up with their reservations forces Harvey from New York, Mistral from Paris, and Sheng from Shanghai to share a room with the hotel owner’s daughter, Elettra. The four kids discover an amazing coincidence—they all have birthdays on February 29, Leap Day. That night, a strange man gives them a briefcase and asks them to take care of it until he returns. Soon afterward, the man is murdered. The kids open the briefcase. In it they find a series of clues that take them all over Rome, through dusty libraries and dark catacombs, in search of the elusive Ring of Fire, an ancient object so powerful that legend says even a Roman emperor couldn’t control it. In the first book of the Century quartet, Italian author P. D. Baccalario begins a mystery that will take four cities and four extraordinary kids to solve.

In the second installment of the Century Quartet, Italian author P. D. Baccalario continues the mystery that will take four cities and four extraordinary kids to solve. Four kids. A wooden top. And four postcards with secret instructions. New York City, March 15 Another mysterious artifact reunites Harvey from New York, Elettra from Rome, Mistral from Paris, and Sheng from Shanghai in their attempt to save the world. When they meet people who knew Alfred Van Der Berger, the murdered professor who sent them on their quest in Rome, they realize that the challenge is far from over. And when they discover a series of four postcards written in code years ago by the professor himself, their destiny becomes even clearer. The cards send the kids all over New York City, through old libraries and abandoned tunnels, in search of the Star of Stone, an ancient object fundamentally connected to the earth. But a new set of villains, predators of Manhattan nightlife, will do anything to stop them.... From the Hardcover edition.

In the third installment of the Century Quartet, Italian author P. D. Baccalario continues the mystery that will take four cities and four extraordinary kids to solve. PARIS, JUNE 20 When new information turns up about the Star of Stone, the object they found in New York, Mistral, Elettra, Harvey, and Sheng meet again in Paris. Harvey brings the stone to show to his dad's archaeologist friend. And it turns out that the friend knows much more about the kids' quest than they could have imagined. She gives them a clock that once belonged to Napoléon, and she tells them that if they can figure out how it works, it will lead them to another object of power. The clock sends the kids all over Paris, through old churches and forgotten museum exhibits, in search of an artifact linked to the Egyptian goddess Isis. But a woman with a penchant for venomous snakes and carnivorous plants—and her vast network of spies—is watching their every move... Fans of Blue Balliet, Trenton Lee Stewart, and Michael Scott will be drawn to this Da Vinci Code -like adventure for kids.

In the fourth installment of the Century Quartet, Italian author P. D. Baccalario concludes the mystery that took four cities and four extraordinary kids to solve. SHANGHAI, SEPTEMBER 19. As the equinox approaches, Sheng, Elettra, Harvey, and Mistral know they must come together one last time. Armed with only a map and a top that seem to be broken, a collection of old coins, and a tile with four knives painted on it, the four kids meet in Shanghai to try to make sense of clues that their predecessors couldn't decipher. Meanwhile Sheng is haunted by a dream and by visions of a young boy who seems to understand their quest. The visions send the kids all over Shanghai, through abandoned water ducts and ancient tea houses, in search of the Pearl of the Sea Dragon, an ancient stone that they're sure is the last piece of the puzzle. But a germophobic supercriminal who never leaves his sterile Shanghai skyscraper will do anything to learn their secrets... Fans of Blue Balliet, Trenton Lee Stewart, and Michael Scott will be drawn to this Da Vinci Code -like adventure for kids.