In a shadowy antiques shop in Rome, violinist Julia Ansdell happens upon a curious piece of music—the Incendio waltz—and is immediately entranced by its unusual composition. Full of passion, torment, and chilling beauty, and seemingly unknown to the world, the waltz, its mournful minor key, its feverish arpeggios, appear to dance with a strange life of their own. Julia is determined to master the complex work and make its melody heard. Back home in Boston, from the moment Julia’s bow moves across the strings, drawing the waltz’s fiery notes into the air, something strange is stirred—and Julia’s world comes under threat. The music has a terrifying and inexplicable effect on her young daughter, who seems violently transformed. Convinced that the hypnotic strains of Incendio are weaving a malevolent spell, Julia sets out to discover the man and the meaning behind the score. Her quest beckons Julia to the ancient city of Venice, where she uncovers a dark, decades-old secret involving a dangerously powerful family that will stop at nothing to keep Julia from bringing the truth to light.


小提琴家茱莉亞‧安斯德爾意外在羅馬一間隱密的古董店偶然看到《火焰圓舞曲》，她隨即迷上這份樂譜的獨特曲式。整首圓舞曲時而熱情奔放，時而痛苦糾結，矛盾交織的旋律，反而呈現令人顫慄之美。樂曲一下用傷感的小調，一下又用急促的琶音穿插交錯，好似舞出了自己奇特的生命。茱莉亞決心要掌握這首複雜的作品，讓世人聽到它的美。她回到波士頓後，演奏起圓舞曲，當琴弓劃過琴弦，激揚的旋律不只在空中迴盪，還引發了奇異事件，連她的生活也受到威脅。這首曲子隱含影響人的可怕魔力，完全改變了她女兒。茱莉亞確信這催眠般的圓舞曲帶有惡意的魔法，她決定要追查樂譜的作曲家以及其背後的意義。她追著線索來到古城威尼斯，也揭開了一樁深埋數十年的黑暗祕密，而且一個危險的權貴家族也涉入其中，他們會不計一切，阻止茱莉亞將一切攤在陽光下。