The mystery

"When the old man who lives in Rourke Castle dies mysteriously, troubletwister twins Jack and Jaide Shield find themselves drawn into a search for something hidden in the castle--something that The Evil wants desperately--but they have no idea what it is they seek."@en
"When the old man who lives in Rourke Castle dies mysteriously, troubletwister twins Jack and Jaide Shield find themselves drawn into a search for something hidden in the castle-- something that The Evil wants desperately-- but they have no idea what it is they seek."
"Born to protect the world - or possibly blow it up! When Grandma X is put out of action by an accident that may or not have been caused by The Evil, it's up to Jack and Jaide Shield to help their father recover a lost Golden Card from Portland's strangest landmark: The Rourke Castle. Negotiating secret passages, talking parrots and animated suits of armour is all in a day's work for the troubletwisters, whose Gifts are steadily coming under control. But agents for The Evil are everywhere, including one apparently masquerading as an old and trusted friend."