Imaikkaa Nodigal (transl. Unblinking Seconds) is a 2018 Indian Tamil-language action thriller film written and directed by R. Ajay Gnanamuthu. It stars Nayanthara, Atharvaa, Raashii Khanna marking the latter's debut in Tamil cinema and Anurag Kashyap with Baby Manasvi, Vinoth Kishan, Ramesh Thilak and Devan in supporting roles, while Vijay Sethupathi has an extended cameo. The film focuses on how a serial killer is apprehended by a CBI officer.

Filming took place between October 2016 and December 2017. The music was composed by Hiphop Tamizha, cinematography by R. D. Rajasekhar, editing by Bhuvan Srinivasan, and produced by C. J. Jayakumar. Imaikkaa Nodigal was released on theaters on 30 August 2018 to highly positive reviews from critics and was a commercial success.

A serial killer disrupts peace in Bengaluru by kidnapping, where he goes by the name of the highly notorious serial killer Rudra, who was announced dead five years ago. After another such case, in which the CBI are involved, he declares himself to be alive and not dead. SP Anjali Vikramadithyan IPS, who dealt with the earlier case of Rudra, is re-appointed to deal with him.

Meanwhile, Anjali's brother Arjun Prabhakar, an MBBS doctor from Chennai, is facing a rough time in his relationship with Krithika Rao, a rising model, by accusing her of cheating, and she eventually breaks up with him. To make it up to her, he and his friend Vinoth travel to Bengaluru to meet her. However, Rudra brings Arjun into the game by kidnapping Krithika and broadcasting a live video threatening to drown her unless her father pays the ransom. In an effort to save Krithika, Arjun follows Rudra's orders and gets framed as Rudra, making things much more complicated for him. During the exchange, Anjali shoots the person carrying the ransom, only to discover that it is Arjun. Though both Arjun and Krithika survive, evidence is planted to frame Arjun as Rudra. Anjali is suspended, her family gets placed under house arrest, and DSP Narayan, Anjali's junior takes over the case.

Arjun escapes from the hospital where he is treated and begins his own investigation. With help from CCTV footage, he traces the real Rudra to a hideout filled with extensive research on himself and Anjali. Parallelly, Anjali, through cracking some clues from the lines uttered by Rudra, deduced him to be Martin Roy, the former Assistant Commissioner of Police from Bengaluru, the first IO of Rudra's case, to be Rudra. Arjun fights with Martin but gets injured. Martin reveals himself as the current Rudra and defeats Arjun, leading to a shocking revelation that Anjali herself was the original Rudra and she fabricated the case and Rudra's death five years earlier. Feeling betrayed that he was suspended from the case, having come so close to cracking it, Martin resigned from the police force, went rogue, murdered his wife, and staged three murders of high-profile people, similar to the ones that Rudra had done. Meanwhile, Anjali too deduces Martin's identity as Rudra.

Arjun escapes from Martin's clutches and confronts Anjali over being Rudra. She reveals that her real motive was to avenge the death of her husband Vikramadithyan, as he, along with Anjali, was caught in an accident caused by four influential drug addicted youngsters (Prathap, Ram, Jayanth, and Vineeth), who, instead of helping them, decided to cover up the incident by murdering them. Vikramadithyan was left to die with Anjali. However, a pregnant Anjali survived the accident and gave birth to her daughter, Shalini. To seek vengeance for Vikramadithyan's death, Anjali created a serial killer named Rudra and brutally murdered the four men. After killing the last one, Vineeth, she declares him Rudra and closes the case. Martin witnessed her actions and later adopted the Rudra identity to continue his own vigilante killings.

Arjun feels guilty, not knowing the pain his older sister had suffered. Meanwhile, Martin targets Krithikaa to erase the last witness who could clear Arjun's name. In a final confrontation, Arjun fights and distracts Martin long enough for Anjali and Narayan to arrive with their force. Martin, who has already fired multiple times at the ambulance in which he thought Krithikaa was being taken by Arjun, asks Narayan to check Krithikaa's condition only for Arjun to reveal that he and Anjali, having realized Martin's schemes beforehand, had devised a new plan with the help of Arjun's friends, brilliantly planting evidence at Martin's home and planned on saving Krithikaa, who Arjun reveals to have been already taken to Malaysia for treatment, while also proving Martin as Rudra in the eyes of CBI and the Media. Realizing that he has been outsmarted yet again, an enraged Martin attempts to shoot Arjun down. However, Arjun kicks the gun off his hand, and Narayan shoots Martin dead. Before Martin passes away, Anjali goes close to him and whispers in his ear that had he known the reason for her taking on the identity of Rudra, he would not have thought of even donning the mask.

The film ends with Krithika and Arjun reconciling, while Anjali and Shalini listen to the recording of her father's last words for her.