François Sentinelle has two lives. By day, he is the most famous cop of Réunion Island, known for his tough methods and flowery shirts, pursuing criminals in his famous yellow defender. But the rest of the time, Sentinelle is also a charming singer.

Transferred home after a traumatizing combat mission, a highly trained French soldier uses her lethal skills to hunt down the man who hurt her sister.

After completing his military training, young Léo, a taciturn soldier with family problems and secret addictions, is assigned to one of the units that patrol the streets of Paris in search of possible terrorist threats as part of Operation Sentinelle.