Retired art and music historian Megan Crespi is traveling across Europe doing research for a book on Cosima Wagner, daughter of Franz Liszt, wife of Richard Wagner, and defiant protector of Bayreuth's Wagner theater and its Wagner-only operas. With Megan are three colleagues from the fields of museums, music, and photography who had previously joined her in an investigation of composer Fanny Mendelssohn. Switching their group name from the "Mendelssohn Quartet" to the "Wagner Quartet," they soon become bound up in a series of anti-Wagner protests that quickly grow from harmless picket lines to physical sabotage of opera houses presenting Wagner operas. The Quartet's travels take them from London and Paris to Leipzig, Dresden, Riga in Latvia, Weimar, Zurich, Tribschen on Lake Lucerne, Munich, Bayreuth, and finally to Venice where Richard Wagner died a sudden death in 1883. Perhaps Megan's richest discovery on this trip was the unearthing of Wagner's forgotten first wife of some thirty years, Minne Planer. How will this affect her book on Cosima Wagner?