When her grandfather dies, a young women goes through his personal effects and finds a side to the man she never knew. Reading through his letters, newspaper cuttings and photographs, she pieces together the story of his involvement as a volunteer on the Republican side in the Spanish Civil War. After a rousing presentation to the local Communist Party members in Liverpool of the situation facing the workers in Spain, David (Ian Hart) out of work and on the dole believes he can do something worthwhile by going to Spain and fighting for the land-working population in their struggle against Franco's military dictatorship which has usurped the power of the democratically elected Socialist government. Unable to get international support for their struggle against the Fascist dictatorship which is supported by Hitler and Mussolini and even tacitly by the British government, many men, like David, make the secret crossing into Spain Americans, Irish, Italians, French and even Germans young idealists all willing to fight for the cause. Together with Spanish workers, they form a Republican militia unit and set about liberating towns in the Aragon region from Fascist control. But more than that, the militia and the people want revolution to impose the communist ideal, collectivising land, improving productivity and sharing it with those fighting for the Republican cause.