Liza is in Moscow with her aunt and uncle whom she dislikes heartily. She had accepted their invitation because her earlier visit with her father - later shot in Washington - had intrigued her with the City. She sees a clown at the circus and becomes interested in him. She goes to the circus three times, finds out he wants to defect to the West, and helps him do so. A suspenseful story with excellent detailed background of life in Moscow.
Librarian Note: There is more than one author in the Goodreads database with this name.
This is not the Shark Tank celebrity, but an author of children's books. The books are mostly realistic fiction about older children and teens who come from families that are dysfunctional or at least face interesting challenges.
Also used the pseudonym Paige Dixon and Gail Hamilton.