In the first leg of his quest, Michael explores the Spanish Basque region, an area that has fought to maintain its own independence and unique culture, and which is integral to Michael's own heritage. His Spanish father and Scottish mother met through their shared interest in helping Basque refugee children who had fled to Britain after the bombing of Guernica during the Spanish Civil War.

Michael's Pyrenean quest continues with the physical challenge of the French High Pyrenees, which he enters at the Cirque du Gavarnie, a 1,700-metre-high wall of limestone forming a natural amphitheatre. He struggles on across the snowy Plateau de Saugué to meet Marion Clignet, a French Olympic cycling champion who refused to let her epilepsy curtail her career, as well as finding time to reflect on his time as defence secretary, and on the current war in Europe.

Michael Portillo continues his Pyrenean challenge, this time in the wild beauty of southwest France's Ariege region. He begins by visiting a young couple from Luxembourg who left city life behind to become pig farmers. Climbing higher into the mountainous terrain, he shelters in a mountain cabin with seasoned hiker Patrice Tessiere Dufour. Michael ends his day at an abbey in the company of Benedictine nuns.

For the final leg, Michael is back in the Catalonian Pyrenees for a deeply personal journey. In 1939, his father Luis Gabriel Portillo Perez fled through these mountains as a political refugee from the Spanish Civil War. At the tiny village of La Vajol, where many refugees headed to cross the border into France, Michael meets Margaret, some of whose family escaped through here.