An impressionistic survey, scripted by Dylan Thomas, of Wales at war. Continuity is provided by film of the Welsh countryside, which underlines the imagery of 'mountains' in which the whole film is couched: the balance of the film, which exists principally to illustrate the soundtrack, shows the castles left by the old war (against England), as an introduction to the new war - steelworkers - dockers - pithead scenes from the Rhondda mines - agriculture - sheep farming - agricultural research at Aberystwyth - quarrying - Welsh chapels - children - women (sewing, and at the whist drive) - Druids. Film concludes with a reminder of recent Welsh history - the social and economic changes that industry brought to the valleys, and the hardships of the depression, from which only the arrival of new industry with the war brought relief - "Remember the march of the old young men/It shall not happen again."