Moordvrouw - Season 2 Episode 4 Stille wateren, diepe gronden

On a construction site a coffin is found during excavation work involving the body of a woman who has been missing for years. All traces indicate that they are buried alive. Then several boxes are excavated in the same area. Fenna and her team find out that a serial killer buried his victims alive, who has dumped for years. Then, Commissioner Vreeswijk suddenly disappears. Has she become the victim of this ruthless killer? And can she still be saved?