Jennifer Arnold is always getting her identical twin, Maggie, in trouble. Life's been difficult in their household since their pilot father went missing, and things get even worse when Jennifer finds an ancient spellbook and learns to become invisible. Then the girls get a wonderful offer - their Grandmother Arnold takes them on a cruise to the Greek islands and Istanbul. But Grandmother Arnold seems to know a lot more about the world of espionage than an ordinary grandmother ought to. The kids learn that not all the people on the ship are who they seem to be either. What's going on? The holiday cruise quickly turns into a mission to find the girls' father. With each stop, the kids learn new information about his disappearance and the danger he's in. Full of hijinks and spy drama, this is Cora Taylor's most electrifying story yet.

Cora Taylor is one of Canada's best-known children's authors. She has published more than a dozen juvenile novels. Cora's Coteau titles include the very successful "Ghost Voyages" series and the "Spy Who Wasn't There" series, which includes Adventures in Istanbul and Murder in Mexico as well as her latest book, Chaos in China.