The film tells the true story of Solomon Northup (played by Chiwetel Ejiofor), a free black man who was kidnapped and sold into slavery in 1841. For 12 years, Northup endured the harsh conditions of slavery in Louisiana, working on plantations and struggling to regain his freedom. The film follows his journey, highlighting the cruelty and brutality of slavery, as well as the resilience and strength of the human spirit.