A student gets embroiled in a dangerous spy plot while on a European tour in this classic YA suspense novel by a New York Times -bestselling author.

Bound for a summer in Europe, fifteen-year-old Nan Russell from Kansas knows her parents are worried about her safety. But what could be safer than a guided tour? It will be led by the distinguished professor Dr. Neal Yates, and the chaperone, Mrs. Stimson, is a friend of the family. The group will see Paris, London, Rome, and Vienna. Everything will be fine.

Unfortunately, the moment Nan lands in New York City, she finds herself in the wrong place at the wrong time. Alone in a gallery at the Metropolitan Museum of Art, she witnesses something she shouldn't. Soon a series of bizarre events embroil her and her tour group in a dangerous plot to kidnap Dr. Yates.

Now Nan needs answers. What would a criminal want with the professor? And can she stop them before they want her as well? One thing Nan knows for certain is that her parents were right to be worried...

Originally published in 1969.