Sharpe, [Sean Bean], and his men rout a group of French soldiers who have ravaged a Spanish village, leaving the inhabitants to pick up the pieces. Two enemies are taken alive, but their commander, Brigadier General Loup, [Oliver Cotton], makes a last-ditch offer to bargain for their fates. Sharpe rejects the deal and has the prisoners executed in front of Loup, who rides away with a burning vow of revenge.
Meanwhile, Wellington, [Hugh Fraser], faces a controversial reinforcement from the King of Spain: the Real Compania Irlandesa (Royal Irish Company), a bodyguard unit made up of Irish-descended troops who are notably undertrained and politically dubious in the eyes of the British leadership. The unit is posted to garrison a fort near the French lines, a strategic yet precarious position that invites desertion if discipline falters. Sharpe is tasked with shaping the men’s discipline and is placed under the command of the unreliable Colonel Runciman [Ian McNeice], a former Wagonmaster-General whose authority is tested from day one.
In camp, Kiely’s wife, Lady Kiely [Allie Byrne], and his mistress, the guerrilla leader Doña Juanita, arrive to complicate an already tense situation. Sharpe uses the time to bolster the fort’s defenses and drill the new troops, while Runciman and the camp’s politics simmer beneath the surface. The Irish unit endures a brutal bombardment that repels Loup’s assault, proving that with resolve and savvy leadership, the fort can hold.
Sharpe then proposes a bold, quick strike on Loup’s headquarters, a plan that gains support from Kiely, Runciman, and the morally dubious influence of Juanita. The situation grows more fraught when Kiely learns his wife is pregnant and orders her to safety, only for tragedy to strike when she is captured. Juanita reveals herself to be a French agent, delivering an ultimatum: Sharpe and his men must press the attack, but Kiely’s loyalty will be tested by the abandonment of the Irish forces for Lady Kiely’s life.
What follows is a tense, near-missed gambit. Sharpe reaches Kiely just as the latter decides to act, and a confrontation ensues in which Sharpe is wounded—shot in the arm by Juanita. Kiely, finally choosing his own conscience over the manipulation around him, strikes back, killing Juanita and exposing the fake newspapers she used to sow disloyalty among the Irish troops. With the truth uncovered, Sharpe and Kiely join forces to assault Loup’s position, while Harper, temporarily in command of Sharpe’s riflemen, uses a ruse to fool the French by pretending to be dead.
The battle ends with a heavy toll on the British side: rifleman Perkins is killed—an event that wounds the camp deeply as he lies beside his lover Miranda. O’Rourke, a rebel within the Irish Company, is responsible for Perkins’ death, and Harper’s response is swift and decisive. In the climactic moments, Kiely is killed by Loup as he attempts to free his pregnant wife, and Loup himself is slain by Sharpe, ending a long cycle of grudges and retribution.
With the conflict resolved, the surviving Chosen Men lay Perkins to rest beside Miranda, a somber tribute to the costs of war and loyalty. Sharpe takes a final, quiet glance at Perkins’s grave before continuing his march forward, bearing the weight of loss, duty, and the endless march of the Riflemen.
