Former commando John de Koning, traumatized by a failed mission in Nigeria, is confronted with a murderer trying to eliminate his former comrades in battle. He starts the fight, but ends up in a war in which he threatens to lose his mates, his family and himself.

The story of Dirty Lines starts in 1987's Amsterdam, at a time when Dutch society was changing rapidly. Psychology student Marly Salomon takes on a side job working for a brand new firm: Teledutch - a company started by two brothers, Frank and Ramon Stigter, who established Europe’s first erotic telephone lines. Frank and Ramon become rich overnight and Marly finds herself immersed in this wild and rapid transformation. The final years of the Cold War sparked a sense of hope and inspired a new generation to celebrate life to its fullest. Amsterdam became the center of that cultural revolution with a radically new form of music: house and a new love drug: XTC. The erotic phone lines offer the opportunity to experience anonymous sex in a new way, changing the morality of its consumers, but also very much the people creating it.

Former Amsterdam police detective Floris Wolfs has been transferred to the police department of the south-Dutch country town Maastricht. His metropolitan experience nicely complements the local expertise of his new country colleagues, who know the folks. Slowly he fits in, while solving countless crimes together with his female partner Eva van Dongen.