iSmart Shankar, a street-smart
assassin, works under another assassin Kaka. One day, Shankar falls in love with Chandini and tries various ways to impress her. Despite being annoyed at first, Chandini reciprocates his feelings. Under Kaka's orders, Shankar kills
CM Kasi Vishwanath and escapes to
Goa with Chandini. However, the cops learn about their location and a shootout ensues in which Chandini gets killed in a cross-fire and Shankar gets arrested. Meanwhile, Sara, a
neuroscientist, is working on
memory transfer and has achieved successful results with
rats. Sara's fianceè Arun, a
CBI officer, is investigating Kasi Vishwanath's death and deduces that a higher force has planned and killed him. Shankar escapes from prison and deduces that Kaka had a major role in Chandini's death and has been ordered to kill Shankar. Kaka tries to escape, but Shankar shoots Kaka in Sara's car. When Arun is about crack the case, he gets killed by the goons. Chandrakanth, Arun's superior and CBI chief, is desperate to know about the killer, where they transfer Arun's memory to Shankar with Sara's help, knowing that Arun's memory will remove his past. Shankar wakes up and experiences memories that are not his own, where he gets enraged after Sara reveals the truth to him and realizes that he will forget about Chandni in a few days. Shankar experiences brief flashes when he becomes Arun, but reverts to being Shankar. Shankar finds Arun's house and discovers a bag that has evidences about the killer, where he calls Chandrakanth to meet him in Goa. When Arun is about to reveal the identity of the murderers, he reverts back to Shankar and escapes with Sara at
knifepoint. After a few events, Shankar reverts to Arun and reveals to Chandrakanth that Kasi Vishwanath's son Devendra and brother-in-law
Central Minister Ramamurthy are the masterminds behind the assassination. Arun devises a plan to arrest Devendra and Ramamurthy with the evidence in
Varanasi. Devendra gets exposed and escapes and Arun follows him, but Devendra and his men continuously beat Arun in his head, which results in Arun getting reverted to Shankar. Sara tells Shankar that Devendra is behind Chandni's death. After an intense fight, Shankar kills Devendra, thus avenging Chandini's death. Sara and Arun leave for
Hong Kong on a vacation and Arun proposes to Sara, who happily agrees, but Arun reverts to Shankar. ==Cast==