Passion - The Musical

Passion is a musical (Broadway 1994), with music and lyrics by Stephen Sondheim and a book by James Lapine. The story was adapted from Ettore Scola's film: Passione d'Amore, itself adapted from the novel "Fosca" by Iginio Ugo Tarchetti.
Set in Risorgimento-era Italy, the plot concerns a young soldier and the changes in him brought about by the obsessive love of Fosca, his Colonel's homely, ailing cousin.