In pre-independence India, Laxman Singh Bisht is a gentle, mentally-challenged boy who is defended by his older brother Bharat Singh Bisht, though his friends still tease him with the nickname “Tubelight.” A sweeping montage follows as the brothers grow up, depicting Gandhi visiting their school, India’s independence in 1947, Gandhi’s assassination, and the death of their parents, moments that deepen their bond even as the country reshapes itself.
In October 1962, the Chinese invasion triggers a wartime push, and the Indian Army begins recruiting camps. From their village, only Bharat Singh Bisht is selected and sent to the Kumaon Regiment. At the border posts, war erupts, and Laxman waits with growing anxiety, racing from post to post in a desperate bid to learn any news about his brother’s status.
A magician, Goga Pasha, arrives in the village and performs a bottle trick that seems to move without touching it. He tells Laxman that the secret behind miracles is faith. The elder Banne Chacha reinforces the idea, declaring, “> Faith moves a mountain,” and urging Laxman to find his own faith rather than fear.
Meanwhile, Bharat is wounded and captured. His escape plan with fellow prisoners falters; he is shot and left unable to move. In a final act of sacrifice, he exchanges his shoes with another soldier to give him a chance to escape, but that soldier is killed as well.
Laxman notices a woman, Le Leing, and a boy, Gu Won, moving into a nearby home. He initially suspects they are Chinese and tries to report them, but Banne counsels him to heed Gandhi’s wisdom and befriend them. After patient effort, he learns they are Assamese, not Chinese, and he begins to see them as kin.
Back at the camp, Bharat’s escape attempt is thwarted, and his comrades are felled. Laxman’s heart aches as he learns of his brother’s capture, while Le Leing comforts him and Narayan, Narayan, initially urges a harsher stance. Narayan’s insistence on viewing Won as an enemy clashes with Laxman’s belief; Le Leing reminds them that they are all Indians. When Laxman speaks of faith, Narayan challenges him to move a mountain; the earth trembles, signaling Laxman’s resolve.
As a ceasefire finally comes, the army begins to recover the fallen. They discover a body bearing Bharat’s shoe-tag and declare him dead, plunging Laxman into grief and fear that his brother is truly gone. The end of the conflict brings a brief respite, with Le Leing’s father returning and the group bidding farewell to Calcutta. Yet the story hints at a twist: the misidentification of corpses due to interchanged shoes means the tragedy may be avoided.
News soon arrives that Bharat is alive but has lost his memory. At a medical camp, Laxman reunites with Bharat, who slowly recognizes his younger brother, suggesting that memory and faith can endure even amid war’s scars. The film closes on a note of fragile hope, with the brothers bound by unwavering faith as they navigate a country forever altered by conflict and reconciliation.
