In an Italian village during the early 20th century, renowned pianist Francis Ingram resides in an ornate, isolated mansion with his entourage, including his nurse Julie, a musicologist named Bruce Conrad, and an astrologer named Hilary. Ingram, although crippled, is able to play the piano using only his left hand. His wealth and fame provoke envy and tension among those around him. Tragedy strikes when Ingram dies under mysterious circumstances following a fall down the stairs. Chaos ensues as discussions about his will lead to disagreements, particularly between Julie and Ingram's nephew, Raymond, who both stand to gain from the estate. Tensions heighten with rumors of greed and betrayal surfacing as the dark atmosphere casts a shadow over the household.

Shortly after Ingram's death, strange occurrences begin to unsettle the residents of the mansion. Rumors of a supernatural force take hold when the pianist's severed left hand seems to come back to life and begins terrorizing the inhabitants. Each night, the haunting strains of music fill the halls as the disembodied hand appears to move with an eerie will of its own, advancing toward its targets with sinister intent. The fear escalates as members of the household find themselves at odds, gripped by suspicion and paranoia. The unseen terror provokes desperate attempts to uncover the truth behind the inexplicable events as motives are questioned and alliances shift. Doubts about whether these occurrences are real or merely figments of their imaginations add to the growing sense of madness gripping those embroiled in the mystery.