A convert is a person who agrees to cooperate with an enemy in exchange for some benefits. It can be a criminal who cooperates with the police or a policeman who delivers secrets to mobsters. No matter if the convert is the guardian of public order or the bandit it is always perilous game where a life is at stake. Main characters of Converts are Paul Sikora, an experienced officer of Central Investigation Bureau and Blacha - John Blachowski, a mobster from the most powerful gang in Poland. The axis of the series is complicated high risk game which is played between these two protagonists. The policeman tries to convert the criminal and the criminal attempts to corrupt the officer. These two men live on the opposite sides of the barricade, however, they have many things in common. Their occupation ruin their families. Both of them have wonderful wives and they love their children but their life is far away to be perfect. Each of them alone has to straggle with the aversion of their environment and personal weaknesses. They're both in a dilemma. Blacha is torn between the care of his family and the loyalty to the group which he comes from. Sikora is torn between his work and his family for whom he does not have enough time. He is desperate to be a good husband and father and good policeman at the same time. Sikora and Blacha have their own principles which seems never to be broken. However, life writes its own scenario in which some rules have to broken. Next to tension and continuous fight for dominance a thread of understanding appears between them gradually