Mission: Chapter 1 (also marketed as Mission: Chapter 1 – Achcham Enbadhu Illaiye; transl. There is no fear) is a 2024 Indian Tamil-language action thriller film directed by Vijay, co-written by A. Mahadev and produced by Lyca Productions, Shri Shirdi Sai Movies, New March Fast Pictures and Aspen Film Productions (P) Ltd. The film stars Arun Vijay, Amy Jackson and Nimisha Sajayan alongside Abi Hassan, Bharat Bopana and Iyal in the supporting roles. This marks Jackson's comeback Tamil film after a five-year hiatus.

The film was officially announced in October 2022 under the title Achcham Enbadhu Illaiye, but the title was later announced as Mission: Chapter 1 – Achcham Enbadhu Illaiye in April 2023 after a production change. Principal photography commenced in October 2022 and wrapped in February 2023. The music was composed by G. V. Prakash Kumar, cinematography was handled by Sandeep K. Vijay and editing by Anthony.

Mission: Chapter 1 – Achcham Enbadhu Illaiye was released on 12 January 2024, during Pongal weekend, to mixed-to-positive reviews from critics and became a box office success.

V. Gunasekharan (aka Guna, Arun Vijay) is a man from Chennai, India. His daughter, Sana, suffers a severe accident and urgently needs surgery in London. Due to the lack of time, Guna cannot transfer the operation cost through legal means, so he turns to a money-laundering agency for help.

After depositing the money in India, the agent gives him a ₹10 note — a symbolic token that allows him to withdraw the money from their branch in the UK. Guna quickly flies to London and gets Sana admitted to the hospital. Thomas, a staff at that hospital who is a drug addict willing to do anything for money, overhears that Guna used a money-laundering service and plans to steal the ₹10 note. He and his gangster friends ambush Guna, attempting to rob him. However, Guna fights them off. When the police arrive, Guna — still defending himself — accidentally punches an officer and is arrested for assaulting a police officer.

Now detained, Guna pleads with the jailer, Sandra James (Amy Jackson), to grant him one day of leave so he can sign the necessary documents for his daughter’s surgery. Sandra, however, denies his request.

Meanwhile, Omar Quadri (Bharat Bopana), leader of the notorious terrorist group Lashkar-e-Taiba, plans to attack the same jail to rescue three of his imprisoned men. Omar hacks into the jail’s automated systems, cutting communications, jamming mobile signals, shutting down the electric fences, and unlocking all cell doors. Chaos erupts as prisoners riot and guards lock themselves inside offices for safety.

Despite his desperation to reunite with his daughter, Guna does not attempt to escape. Instead, he uses his exceptional combat skills, tactical intelligence, and knowledge of prison operations to take control of the situation. Working with Sandra and other staff, he stops the mass escape and discovers Omar’s true plan — the riot was merely a diversion. The real objective was to free three specific prisoners through an alternative escape route. Guna manages to intercept and capture them.