- Directors: George Stevens
- Producers: George Stevens
- Writers: Rudyard Kipling, Ben Hecht, Charles MacArthur, Joel Sayre, Fred Guiol
- Genres: Action, Adventure, War
- Actors: Cary Grant, Victor McLaglen, Douglas Fairbanks Jr, Eduardo Ciannelli, Sam Jaffe, Joan Fontaine
On the Northwest Frontier of colonial India, circa 1880, contact has been lost with a British outpost at Tantrapur in the midst of a telegraph message. Colonel Weed (Montagu Love) dispatches a small detachment of British Indian Army troops to investigate, led by three sergeants of the Royal Engineers, MacChesney (Victor McLaglen), Cutter (Cary Grant), and Ballantine (Douglas Fairbanks, Jr.), long-time friends and veteran campaigners. Although they are a disciplinary headache for their colonel, they are the right men to send on a dangerous mission. Accompanying the detail is a regimental bhisti (water-bearer), Gunga Din (Sam Jaffe), who longs to throw off his lowly status and become a soldier of the Queen.
They find Tantrapur apparently deserted and set about repairing the telegraph. However, they are soon surrounded by hostile natives. The troops fight their way out. Colonel Weed and Major Mitchell (Lumsden Hare) identify an enemy weapon brought back as belonging to the Thuggee, a murderous cult that had been suppressed for many years.
Ballantine is due to leave the army in a few days to wed Emmy Stebbins (Joan Fontaine) and go into the tea business, a combined calamity that MacChesney and Cutter consider worse than death. Meanwhile, Gunga Din tells Cutter of a temple he has found, one made of gold. Cutter is determined to make his fortune, but MacChesney will have none of it and has Cutter put in the stockade to prevent his desertion. That night, Cutter escapes with Din’s help and goes to the temple, which is all that Din had claimed. Unfortunately, they discover that it belongs to the Thugs when the owners return. Cutter creates a distraction and allows himself to be captured so that Din can slip away and sound the warning.
When the regiment comes to the rescue, the guru boasts that they are marching into the trap he has set, with the three sergeants as bait. He orders his men to take their positions, but when he sees that they are unwilling to leave him in enemy hands, he leaps to his death in a pit full of cobras to remove that obstacle. Thugs then climb the temple and overwhelm the soldiers, shoot and bayonet Cutter. Gunga Din is also bayoneted, but manages with the last of his strength to climb to the top of the gold dome of the temple and sounds the alarm with the bugle. He is then shot dead, but the British force is alerted and defeats the Thuggee forces. At Din’s funeral pyre, the colonel formally inducts Gunga Din as a British soldier and reads the last lines of the Kipling poem over the body: