Serial killer dramas have a grimy reputation. The phrase conjures up lurid magazine headlines promising Sick! Twisted! Depravity! and Never-Seen-Before Crime Scene Photos! Think ‘true crime serial killer’, you think of Jack the Ripper tours and David from Psychoville poring over victim stats and working himself to a froth over all the gory details. To shake off those associations and emerge as nuanced, intelligent and non-exploitative, a drama has to work hard. It has to foreground the human cost and trace a story that doesn’t revel in gore. It requires scripts that build in context and narrative balance. It needs empathy with the victims, and a central performance that captures the horrid anomaly of the killer without lending rock star glamour. Most of all, it needs a purpose other than as a ratings draw. Des does and has all of the above. Luke Neal, Lewis Arnold and co. have made a considered, responsible serial killer drama that’s gripping for its human insights, not its portrayal of inhuman perversion. The hour seamlessly integrated archive news footage, and, as is traditional in trial episodes, seemed to show the tide turning in Nilsen’s favour before the final vindication. The defence discredited witnesses – cruelly and homophobically in the case of escapee Carl Stottor – and the prosecution’s lack of evidence relating to motive created jeopardy. That there was jeopardy at all in the episode is a testament to this drama’s skill. Few people watching Des can have been unaware of the fact that Nilsen died in prison while serving multiple life sentences. We already knew the ending, yet the finale was never less than captivating. That was down to performance. Episode three contained this cast’s best work. David Tennant has been masterful throughout, and in the finale, Jason Watkins and Daniel Mays were given material that showed they’re every bit as good. Incidentally, also terrific both on and off the witness stand was Laurie Kynaston as Stottor. He’s one to watch. Watkins’ growing discomfort around Nilsen and increasing antagonism towards him made their scenes compelling. There were big, dramatic confrontations as well as small but equally revealing moments like the shot of Masters drinking at a bar after Nilsen’s conviction, his back to the camera, seeming to dab away a tear. The climactic moment in which Masters told Nilsen that the book was not his, and had not been written as a celebration but as a warning, was excellent drama. Nilsen’s reaction? A change of subject and a casually devastating confession designed to shift the balance of power back in his direction. Well-acted, well-written moments like that were a stronger insight into Nilsen’s psychology than any number of speeches on the witness stand. A continued focus on DCI Jay and his team’s attempts to bring closure to the victims kept Des honest and empathetic. Jay anchored the story in humanity, and Mays was the perfect actor to play him. The drama’s choice of final screen caption told us where its heart lay – not anywhere near Nilsen, but with the victims. That list of eight dead men and boys’ names was a throat-punch of emotion, and gave them the last word. As a serial killer drama, Des, avoided all the pitfalls. It was neither sensationalised nor lurid, cheap nor prurient – not a celebration, but a warning.