Aged 13, Pat is a gifted young athlete beloved by his community and is already running everywhere in County Mayo, a very fit young lad who wins every race simply because he refuses to slow down. When he skids into the yard of his uncle Johneen’s cottage, British soldiers are tossing furniture onto a blaze and levelling the roof for non-payment of rent. Pat’s father, William Nally – respectable Catholic agent to another landlord Sir Robert Lynch-Blosse – can do nothing. The boy’s indignation hardens into purpose. Johneen clasps his shoulder and tells him to just keep running.

Pat grows to manhood and his athletic prowess and fiery spirit draw the attention of nationalist leaders, including Thomas Kelly, Michael Davitt, Charles Stewart Parnell, and Michael Cusack, who recognise in Pat a symbol of Ireland’s resilience and hope. From here the strands tighten. Kelly sends Pat to Westport where Michael Davitt, one-armed veteran of British prisons, rouses farm labourers beneath a Land League banner while the bearded parliamentarian Charles Stewart Parnell courts polite society in Dublin, promising Home Rule through ballots, not blades. Pat stands between them: an athlete who can fill a field with boys eager to run, and a sworn Fenian ordered to fill the same field with recruits. He walks the line, hoping sport can be his armour.

Pat organises an illegal sports day on his family’s land, defying English landlords and authorities who seek to suppress Irish culture and autonomy. His challenge culminates in a high-stakes race against Captain Doughtie, symbolising the cultural and political tensions of the time. Pat wins. The ruggedly handsome Doughtie finds himself torn between duty and growing sympathy for the Irish cause – particularly as he develops complex feelings for Celia. Alfie Coleman, a seemingly friendly gamekeeper who takes charge of proceedings, becomes a key player in Pat's story, his true loyalties and ulterior motives hidden beneath a genial exterior.

Meanwhile Celia and Doughtie circle each other with wary fascination. He quotes Robert Emmet and confesses a love for Ireland that shames his scarlet coat; she believes him – almost. Coleman’s harvest-dance party turns boisterous and Pat, normally abstemious, is bullied into drinking poitin and staggers home mortified. Celia leaves early and Doughtie waylays her in the moonlight, blurts his love, steals a kiss; they struggle and she slaps him hard enough to draw blood. She gallops off on his own horse, her cheeks aflame with equal fury and desire. Coleman witnesses this, and ponders his next move. 

Parallel to Pat’s journey, the assassination in Dublin's Phoenix Park of Lord Frederick Cavendish and Thomas Burke by 'The Invincibles' underscores the escalating conflict between Irish nationalists and British authorities. After a tip-off from Coleman that a local landlord's agent George Hawkshaw Scott is going to be targeted by a gang the following night in the nearby town of Crossmolina, Pat and a few of his young followers travel by boat to the northern end of Lough Conn in an attempt to thwart his would-be assassins. However, the killers' plan ends in mayhem and Pat – who fires a gun to scare them off – is framed and is arrested and charged with attempted murder! 

Upon hearing the jury pronounce the verdict, Colonel Kelly slips away out of the courtroom, not waiting for the sentencing to be announced... he has other plans. Pat is sentenced to ten years imprisonment and the courtroom is in uproar – Pat's family, Celia and friends are devastated. Two prison guards lead Pat down to a holding cell beneath the courtroom – but stop in their tracks immediately on entering. The room is full of rebels with guns, and the prison staff are both gagged and tied to chairs.  Leading the welcoming group is a smiling Colonel Kelly. Pat is sprung from captivity.

Then, Kelly remounts his horse and heads off to track down the traitor Coleman... and executes him.