Detective Hole ending explained: Who was the killer and what happened to Waaler?

*Warning – contains full spoilers for all nine episodes of Detective Hole.*

All nine episodes of Detective Hole are available to watch now, with Jo Nesbø's iconic detective being brought to life by Tobias Santelmann, in a twisting, turning series.

Based on the fifth book in the Harry Hole series, The Devil's Star, this season sees Harry trying to take down a serial killer operating in Oslo, while also exposing the criminal acts of his nemesis and colleague, Tom Waaler.

But did Harry succeed in bringing down Waaler in the end, and what happened to him? Plus, who was the serial killer terrorising the streets of Oslo?

Read on for everything you need to know about the ending of Detective Hole season 1.

Detective Hole ending explained: Who was the killer?

In the penultimate episode of Detective Hole, it was revealed in a shocking twist that the killer was actually Willy Barli, the husband of Lisbeth.

Harry had found this out because seeds found under Lisbeth's fingernail, on the finger that had been chopped off, came only from a cafe Willy had visited the same day it was found. Harry deduced that Willy had killed her, chopped off her finger and put it up his anus after she had died, rather than her putting it up there herself before, as he had claimed.

He had found out his wife had started an affair with Martin Aminov on their honeymoon, and had determined to make them both pay by killing Lisbeth and framing Aminov for the murder.

He also killed three others and added rituals to the proceedings, so as to detract attention away from himself – if it was just Lisbeth that was killed, he would have been the prime suspect, but the presence of a serial killer muddied the waters.

Aminov had previously tried to sell the Barlis a star-shaped diamond, so Willy had said he was in the marked to buy multiple of then, in order to find Aminov.

Aminov dropped the diamonds off at a discreet location for Barli at specified times, so the latter could ensure the former wouldn't have an alibi for all the murders he was committing. Barli then recorded messages on cassettes while adopting an accent, and left them at the crime scenes, along with the stars, to implicate Aminov.

Harry confronted Barli about this, and the killer almost took him out too. However, Harry later found him having fallen on to a spike outside his home – seemingly having jumped, but it wasn't clear how this played out.

What happened to Tom Waaler?

In the final episode, as Harry got closer to Tom Waaler's dark secrets, the latter kidnapped Oleg, knowing what he meant to Harry.

Harry and Waaler arranged to meet, which they did along with Aminov, who held the key to exposing Waaler's crimes. Harry handcuffed himself to Aminov and made it look as though he had swallowed the key. He then revealed to Waaler that he had caught him on camera, holding a gun to them.

Waaler argued he could spin it and told Harry, Aminov and Oleg to get in the elevator. Harry had stashed a gun in there, but Waaler had found it and got rid of it.

A brawl ensued and Waaler tried to bust into the lift as they were going up in it. Aminov had un-cuffed his hand with the real key, so Harry attached that cuff to Waaler's arm. As the elevator went up, Waaler found himself outside of it but attached to Harry, meaning his arm was ripped off.

Undeterred but bleeding out, Waaler went up the stairs to find Harry and died as the two of them looked at each other through a window.

Later, the final scene of the episode saw Harry looking into Tom's past, speaking to a shopkeeper who knew him when they were both children. From his recollection of rumours and reports at the time, it seemed that Tom had been abused by his father, and had killed him as revenge, making it appear like an accident.

This added a tragic lens to everything we already knew about the complicated character.

Where did we leave Harry Hole?

At the end of the season's final episode, the deputy chief of police Agnes Kittelsen met with Harry and tried to convince him to return to the police force. She said that she needed him to help root out the rest of the underground network of corrupt cops that Waaler was a part of.

He was initially reluctant, but based on his experiences with Barli and his conversation with Kittelsen, he was finally able to uncover the truth about what happened with the bank robbery/murder case which had plagued him for so long.

Beate managed to identify Stine's husband as her killer. He had never been on the list of suspects until this point because the killing was so associated with the bank robbery. However, the robbery itself was actually just one big diversion to kill her.

He had also resumed his relationship with Rakel, and it seemed like things were heading on the right track.

However, a crucial scene at the end of the episode revealed that, unbeknownst to Harry, Kittelsen was a part of the same network as Waaler. She had been trying to recruit Harry and get him to report directly to her, so he would keep Waaler's actions, and the existence of the network, quiet.

Speaking to another member of the organisation, she vowed to lay low for a while but then regroup and come back stronger than ever.

Detective Hole is available to watch in full on Netflix now. Sign up for Netflix from £5.99 a month. Netflix is also available on Sky Glass and Virgin Media Stream.

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