In 1879, a small detachment of British soldiers from the 24th Regiment of Foot occupies a supply depot at Rorke's Drift in Natal, a region of South Africa. The garrison, largely composed of Welsh infantrymen, is led by the brusque but capable Lieutenant John Chard of the Royal Engineers, who is joined by the by-the-book Lieutenant Gonville Bromhead. As they settle into the remote outpost, news arrives that the British army has suffered a catastrophic defeat at the hands of the Zulu Kingdom at the Battle of Isandlwana. Subsequently, the soldiers at Rorke's Drift are warned that a large Zulu force is advancing on their position, aiming to eliminate the British presence in the region.

The men of Rorke's Drift hastily fortify their station with mealie bags and biscuit boxes as swarms of Zulu warriors emerge upon the horizon. With limited manpower and resources, but a firm determination to stand their ground, the small British force prepares to face the approaching onslaught. As the Zulus execute their war chants and display their fearsome battle regalia, the tension among the defenders rises, and the reality of the dire situation becomes apparent. The stage is set for a desperate and disproportionate conflict, where strategy, leadership, and bravery must overcome overwhelming odds.