"Strange things are going on at the Paris Opera House: a mysterious phantom--a skeleton in dinner dress--is wreaking havoc amongst the singers and the backstage staff. When new managers take over, and dismiss the rumours of the Opera Ghost, the terror really begins. Who is the mysterious figure stalking the stage at night? How can he be everywhere at once, and enter and leave locked rooms at will? And what is his connection to the beautiful and talented...

Facing expulsion from school and a lawsuit after a prank gone wrong, Linc Baker strikes a deal with two secret agents that show up on his doorstep. They'll make Linc's troubles go away, but only if he'll impersonate a kid agent that went missing while on a mission.

When authorities threaten to take Sophie, twelve, from Charles who has been her guardian since she was one and both survived a shipwreck, the pair goes to Paris to try to find Sophie's mother, and they are aided by Matteo and his band of "rooftoppers."

While vacationing in Paris with her friends Beth and George, seventeen-year-old Nancy pursues a mystery involving a puppet theater and a long-lost treasure.

In fifteenth-century Paris, a disfigured man named Quasimodo, who was abandoned as an infant in the cathedral of Notre-Dame and now lives in its bell tower, must come to the aid of a beautiful gypsy girl named Esmeralda after she repels the advances of the cruel archdeacon Don Claude Frollo.

Now in Paris with her parents who are filming their TV show about the world's haunted cities, Cassidy Blake (who can see ghosts) and her friend Jacob (who is a ghost) are alert for trouble, especially when the filming takes them into the underground Catacombs, the empire of the dead, where Cassidy accidentally awakens a powerful poltergeist spirit--one whose mystery she must solve before his power in unleashed on the whole city.--