Nancy receives an urgent message from her father, Carson Drew, while she is touring in Europe with a group from Emerson College.
She and her close friends, Bess and George, fly immediately to Italy, where Nancy begins her mysterious assignment involving an old Venetian family.
When the girls arrive in Venice, however, they are surprised to find their friends Ned, Dave, and Burt already on the scene — but in jail!
The Emerson boys have been accused of stealing an invaluable collection of antiques.
Nancy must clear their names, despite the mounting evidence against them.