I saw the 2nd part of this on Masterpiece Theater, and it's definitely the best of all 6. In this latest Prime Suspect Helen Mirren uncovers the murderer of 2 Bosnian refugees. The suspect turns out to be a Bosnia Serb war criminal, but is protected by the British government a la Szell in Marathon Man. Jane Tennison is older and wiser as she goes against orders to bring the mass killer turned smooth London professional to justice. The script writing is superior, even to the earlier episodes, as we get this psychological cat and mouse between Jane and the suspect, his wife, and his underling. And as part of the investigation Jane even travels to Bosnia and has the inevitable affair with her assistant. This shows the Bosnian war should not be forgotten and we've got to bring Mladic, Karadic, and the others to justice.