Sainik is the heart warming story about the loss and return of love. Suraj Dutt is the son of Yashpal Dutt who gets married to the beautiful Alka. Alka happens to be Suraj's younger sister, Mini's best friend. Suraj is a dedicated lieutenant in the Indian military force. He carries the legacy of his father Yashpal of serving the nation wholeheartedly. Suraj's family consisted of Yashpal, Mini, Alka, Bihari and Suraj himself. Though Bihari is actualy a servant, he is treated like Yashpal's own brother and also receives due respect. When his holiday stint gets over, Suraj bids adieu to his family and goes back to the Indo - Pakistan border region. There he is given the duty of stopping the smuggling of secret documents of the nation. On this mission, he gets hit by dynamite and his body is not found. His colleagues presume that he is dead. Yashpal is the first to receive the news about his son's death. He decides not to disclose this fact to Suraj's pregnant wife Alka and to his daughter Mini. Alka on the other hand gets the same shocking news from her father and she too decides not to disclose this fact to her father in law and Mini. She feels that the weak hearted Yashpal may die on receiving the news. Mini too gets the news about her brother's death and suppresses the truth from the rest of the family. Bihari gets the news from Yashpal and breaks down. Thus begins a game of deceit by each one of the family members to protect the others from shock, grief and sorrow. Meanwhile, Mini's marriage is fixed with Vijay. Suraj's army friends also come to the wedding ceremony. But every thing seems empty in Suraj's absence. At the end of the wedding the family discloses the secret to each other accidentally. Suddenly a pack of goons come to abduct Mini. Vijay and Suraj's army friends fight with the armed goons. At the last moment Suraj returns and saves his family. The family reunites after months of distress and dejection.