Changeling (Volume 1) (Order of Darkness) 

The year is 1453, and all signs point to it being the end of the world. Accused of heresy and expelled from his monastery, handsome seventeen-year-old, Luca Vero, is recruited by a mysterious stranger to record the end of times across Europe. Commanded by sealed orders, Luca is sent to map the fears of Christendom, and travel to the very frontier of good and evil. Seventeen-year-old Isolde, a Lady Abbess, is trapped in a nunnery to prevent her claiming her rich inheritance. As the nuns in her care are driven mad by strange visions, walking in their sleep, and showing bleeding wounds, Luca is sent to investigate and all the evidence points to Isolde's criminal guilt. Outside in the yard they are building a pyre to burn her for witchcraft....

Stormbringers: Volume 2 (Order of Darkness)

Luca Vero is a member of the secret Order of Darkness, tasked with searching out and reporting signs of the end of the world. Breaking his journey in Piccolo, he finds a place filled with superstitious fears: of the unknown, of the forces of the sea and sky, of strangers. With him are his loyal friend and servant, Frieze, and his clerk, Brother Peter, as well as the Lady Isolde and her mysterious servant-companion Ishraq. The five of them are followed into the town by a huge children's crusade, led by a self-proclaimed saint. Its young leader promises that the sea will part before them, and allow them to walk dry-shod all the way to Jerusalem. Luca and Lady Isolde are swept up in the growing excitement; but something dangerous is brewing far out to sea...

Fools' Gold (Order of Darkness 3): Volume 3

Luca Vero and his friends are plunged into the heady whirlwind of Venice, the world's busiest marketplace, where everything - and everyone - is for sale. Their mission from the Pope is no protection: this city has its own laws. Meanwhile, the Lady Isolde is in more danger than ever, and her feelings for Luca are becoming more intense. As the friends face the unknown dangers of magic and alchemy, the crimes and politics of the city may become the least of their worries. The powers they confront are not of this world ...

Dark Tracks (Volume 4) (Order of Darkness)

Luca Vero is a member of the secret Order of Darkness, tasked by his master to uncover the truth behind strange happenings. Together with Lady Isolde, her friend and confidant Ishraq, Luca’s manservant Freize, and Brother Peter, Luca travels across medieval Europe – seeking out the signs of the end of days, judging the supernatural and testing the new science.Trapped in a village possessed by a dancing madness, the group fights to keep their own sanity. When Isolde dances away in red shoes and Ishraq takes dramatic revenge on their covert assassin the young people discover that the greatest danger is in the men who have come to their rescue. These are the truly dangerous madmen of Europe who carry a dark hatred that will last for centuries. ...