CBI 5: The Brain is a 2022 Indian Malayalam-language mystery thriller film directed by K. Madhu and written by S. N. Swamy. The film stars Mammootty reprising his role as CBI officer Sethurama Iyer along with an ensemble cast. It is the fifth installment of CBI film series.

When a political leader’s sudden death sets off a baffling case for police, it’s up to ace detective Sethurama Iyer to unravel the mystery.