Three-Eyed Ruby (1970)

When a young woman named Shohreh is found dead at a hotel in northern Iran, her death is ruled a suicide, supposedly caused by her unrequited love for Shahin, the hotel's singer. Refusing to believe the official explanation, Shahreh's younger sister, Firouzeh, sets out to uncover the truth and avenge her death. Her investigation leads her to Shahin, who conceals his identity while helping her unravel the mystery. As suspicion grows and the police reopen the case, a tangled web of infidelity, deception, and murder begins to emerge. Along the way, Firouzeh finds herself unexpectedly falling in love with the very man she initially blamed for her sister's death.