Airs Above the Ground — Mary Stewart

Lovely Vanessa March, two years married and very much in love, did not think it was a strange for her husband to take a business trip to Stockholm. What was strange was the silence that followed. She never thought to look for her missing husband in Vienna -- until she saw him in a newsreel shot there at the scene of a deadly fire. Then she caught a glimpse of him in a newsreel shot of a crowd near a mysterious circus fire and knew it was more than strange. It was downright sinister.

Vanessa is propelled to Vienna by the shocking discovery. In her charge is young Timothy Lacy, who also has urgent problems to solve. But her hunt for answers only leads to more sinister questions in a mysterious world of white stallions of Vienna. But what promises to be no more than a delicate personal mission turns out to involve the security forces of three countries, two dead men, a circus and its colourful personnel. And what waits for Vanessa in the shadows is more terrifying than anything she has ever encountered.