You might not have heard of serial killer Dennis Nilsen before watching “Des” — but you’ll never forget him after David Tennant’s creepy portrayal of this pathologic monster dubbed “the kindly killer.”

The chilling three-part series, concluding Thursday on Sundance Now, averaged 11 million viewers when it premiered last month on ITV — the UK network’s best drama premiere in 14 years. Viewers there are familiar with Nilsen’s crimes and how the unassuming Scottish-born civil servant, an ex-cop, was convicted of strangling and dismembering 12 young men (probably more) in London from 1978-83. The case provided plenty of lurid headlines, at least six TV specials and the book “Killing for Company: The Case of Dennis Nilsen,” written by Brian Mast (one of the main characters in “Des”).

It’s Tennant, though, who steals the show. The Scottish actor doesn’t need to concoct an accent to play Nilsen — which adds to the realism — and with the help of a bad haircut and glasses he bears a striking resemblance to the killer, who was sentenced to life imprisonment and died, in 2018, after abdominal surgery. Good riddance.

Daniel Mays and David Tennant in "Des."
Daniel Mays and David Tennant in “Des.”Sundance Now

What’s so creepy is Nilsen’s nonchalance, and the way in which Tennant channels his psychosis. When arrested, he calmly tells  Detective Inspector Peter Jay (Daniel Mays) that “it’s a relief to get this off my chest”; when asked the number of his victims he shrugs his shoulders: “15, or 16, I think.” He’s helpful, but only to a point; he eventually opens up about his murderous M.O. of picking up young men, either homeless or drug addicts, and luring them back to his London lairs (there were two); once there, he strangled them and dismembered their bodies, spending time with the naked corpses before disposing of his prey. He was betrayed in 1983 by a blocked drainage pipe in his house — and you can guess what was found in there and inside Nilsen’s filthy abode (he boiled his victims’ heads, and, in one scene, Jay is warned not to look inside a pot on the stove).

David Tennant in "Des."
David Tennant in “Des.”Sundance Now

Like other familiar serial-killer cases (Ted Bundy, Jeffrey Dahmer, Dennis Rader), Nilsen enjoys the attention, which leads to a cat-and-mouse game with the dogged Jay, who’s intent on solving all the murders but gets blowback from Scotland Yard, which is more worried about funding the investigation and some recent bad press than about providing closure for the victims’ families as more of them come forward, as do several men who escaped Nilsen’s murderous clutches.

What I like about “Des” is that, like many other British dramas, it gets right to the point: Nilsen is arrested minutes into Episode 1 and, while there’s a slight narrative arc regarding Jay’s personal life, it’s not integral to the series and seems to be thrown in there to “personalize” him, which isn’t really needed, since Mays does a fine job conveying Jay’s frustration and determination in bringing Nilsen to justice for each and every murder.

David Tennant and Jason Watkins in "Des."
David Tennant and Jason Watkins in “Des.”Sundance Now

That frustration is fueled, in part, by what Jay and his police colleagues see as unwanted interference from author Mast (Jason Watkins), who’s writing his book about Nilsen and, in their face-to-face jailhouse sessions, is gleaning a lot more information about what turned him into a monster — scenes that will strike a familiar chord with fans of shows such as “Manhunter” and the endless documentaries about Bundy, Charles Manson, et al.

There’s still time to catch up on “Des” before its conclusion on Thursday. You’d be advised to check it out.

https://nypost.com/2020/10/26/david-tennant-stages-a-creep-show-as-serial-killer-in-des/