Anna Obach is a young sub-inspector of the Mossos d'Esquadra, with a brilliant record and a promising future, but with a stubborn character and a keen sense of justice. One day, due to a confrontation with her superiors, she is degraded and destined for Gran Nord, a little-known valley in the Pyrenees. Gran Nord is a special place for city dwellers, but quite normal for the people who live there. What is no longer so normal, not even for the people of Gran Nord, are the inhabitants of the small village of Nord, where Anna arrives to settle in the old and abandoned family home.