In the autumn of 1810, the French forces of Marshal Masséna are invading Portugal and are temporarily halted by the Anglo-Portuguese army under Viscount Wellington at the Battle of Bussaco. As winter approaches, Wellington withdraws his troops towards the fortifications he has prepared in secret at the Lines of Torres Vedras. Using a scorched earth defense, he forces the inhabitants to evacuate the land, destroying all supplies that could be useful to the French. We see the effects on combatants, both regular soldiers and guerrillas, and on the civilian population.