The story follows Abdullah (Mohanlal) who is hired by the members of a wealthy royal family to assassinate the family head Maharaja Udayavarma (Nedumudi Venu). Abdullah comes into the royal palace under the disguise Ananthan Namboothiri, a classical singer, and tries to use this mask to softly kill the Maharaja.

Midhunam movie is all about Sethumadhavan (Mohanlal) who has plans to start a biscuit factory near his house. But the bureaucracy and the corruption of the officials are the hurdles in front of him. Along with that he has to solve the problems in his family, which his brother (Innocent) and brother-in-law (Jagathy Sreekumar) creates. he marries his long-term fiancée Sulochana (Urvashi) who always cribs that he doesn't have love towards her, which he had shown before their marriage. How sethumadhavan succeeds in his life beating all the odds against him forms the rest of the story.