The film has Kamal Hassan in a double role (he has played at least 20 dual roles in films so far) and the ravishing Raveena as a suave newsreader. Nepalese lass Manisha Koirala too plays a glossy cameo in the film. Based on the novel "Daayam" written by Kamal Hassan and directed by Suresh Krishna "Abhay" is at its core the story of an intrepid Major of National Security Guards Vijay Kumar (Kamal Hassan) and his demented twin brother Abhay (Kamal Hassan again, although brawny and sans moustache). Vijay is a highly decorated commando who was raised by his maternal uncle. He has shown his valor in many important security missions and does not hesitate in pulling the trigger when necessary. On one such hijack rescue mission Vijay impresses upon a NDTV newscaster Tejaswini (Raveena) with his intelligence, tactics and presence of mind. Love sprouts between the two and comes to full blossom. Vijay and Tejaswini decide to tie the knot. But before that Vijay wants her to meet the only near-and-dear in his life his demented twin brother Abhay who has been incarcerated in the mental asylum since the young age of twelve for killing his stepmom. Since then he has been ostracized by the society and labeled as a psychotic killer. There is a sad story to the brothers' past. Vijay and Abhay's father Lt. Col. Santosh Kumar (Milind Gunaji) was a characterless and an alcoholic soldier who was infamous for embezzling money in his army section. His careless ways forced his wife to the point of suicide. Rather than bereaved at his wife's death he took in another woman Jayanti (Kitu Gidwani) as the little children's (Vijay and Abhay's) stepmom. But the children did not approve of their new mother, particularly Abhay, who was driven to the point of hysteria. He killed his stepmom. And the killer child grew up into a fearless psychopath killer. However, from the beginning Vijay has always held affection for Abhay in his heart and has tried to free his brother but has met failure all the time. Before he marries he wants Tejaswini to meet Abhay.