Gowri's world is jolted when a spate of murders of teenaged girls in her village seems inexplicably connected to her family's mysterious past. Her problems are compounded when her sister is subjected to smarthavicharam, a trial for adultery for Namboodiri Brahmin women, after being accused by her sister's husband Balaraman. Her sister is convicted, deemed a sathanam (an inanimate object) and given away to the untouchables. Contact with untouchables was forbidden for a Namboodiri, yet Gowri attempts to rescue her sister from the untouchables. For that she needs to fight the Namboodiri social system despite the limitations of a Namboodiri woman. Gowri and her teenaged friends put their own lives in danger as they try to uncover the mystery of their society, which is embedded deeply inside a complex social setup. Black Peppers is a suspense thriller, which is set in 1742 AD in a cluster of hamlets in the southern region of Kerala in India around the time when the then nascent kingdom of Travancore was taking shape. It also marks a period when European powers were jockeying with one another to establish a foothold in Kerala and take control of the spice trade.