Dr. Sethuraman (Suriya) is a reputed scientist and watchmaker who lives with his wife Priya (Nithya Menen) and newborn son Mani in a mansion with a laboratory. In January 1990, he invents a watch using which a person can travel back and forth in time for a maximum of 24 hours. His evil twin brother Athreya (Suriya) tries to take the watch and kills Priya in the process. Sethuraman escapes with Mani and boards a train. Before Athreya arrives, he hands Mani to a passenger named Sathyabama (Saranya Ponvannan) and pleads her to save his son. Athreya kills Sethuraman and is seriously injured in an attempt to escape. Sathyabamas father (Girish Karnad) is against her decision to save Mani, and she leaves with him for Chennai to honour the promise given to Sethuraman. 26 years later, Mani (Suriya) becomes a watchmaker who considers Sathyabama as his biological mother. A paralysed Athreya wakes up from coma and decides to find the watch he hopes to go back to 1990 and save himself from the accident. In a series of incidents, Mani finds Sethuramans watch and explores its powers. Using them, he manages to impress Sathya (Samantha Ruth Prabhu), his client who hails from Sathyabamas native place Gopalasamudram. Athreyas close aide Mithran (Ajay) issues an advertisement offering five crores to the one who finds Sethuramans watch. Including Mani, many prepare the duplicate of the watch and submit them. But Athreya spots Manis design accurate and kills him, thereby gaining possession of the watch.