The Happiest Day in the Life of Olli Maki

The story is about Vishnu, a geologist and his wife, Sumathi, a teacher. They have been married for the past seven years but have not been gifted with a child. Things change once Vishnu falls while carrying out his work in a cave. He then sees a bright ray of light. Since that day he experiences strange incidents around him and his wife. An old man who appears to know what is happening, passes Sumathi a book, telling her to read it and to be careful. It looks like Vishnu and Sumathi are targeted by beings from outer space.