Ulagam Sutrum Valiban Mr. Murugan (M.G.R) is an Indian scientist who has recently discovered how to store a part of the energy unleashed from lightning. He reports this in the Hong Kong scientists' conference. He says that he won't reveal his discovery since the world is at the brink of World War III and his research may be used for destructive purposes. Scientist Mr. Bairavan (Asokan) says Murugan is showing off without researching anything. So Murugan demonstrates it and destroys the vital research notes which upsets the other scientists. Bairavan negotiates with him to sell the research to a foreign country which Murugan refuses. Murugan then departs with his girlfriend Miss Vimala (Manjula) for a world tour. He tells to Vimala that he pretended like destroying the research notes and he has kept the notes in some safe place. He was willing to use them and research further so that his research is used for productive purposes. Bairavan who has been following them hears this and follows them wherever they go. Bairavan wants the research notes so that he can sell them to some countries for a lump sum amount.
In Singapore, Bairavan shoots Murugan with a special gun (not killing him). Vimala faints on seeing this. Murugan became mentally affected and is taken into Bairavan's custody.
Now comes Mr. Raju (M.G.R) a CBCID officer and Murugan's younger brother in Singapore in search of his brother. How he finds his brother and what happens to others form the rest of the story.