Netflix's A Killer Paradox takes a stab at flipping the serial killer genre on its head

Thankfully, a colleague shows up to defuse the situation, except a new argument then erupts between him and Lee after the old man's gone home. It's during the heat of this exchange that Lee suddenly loses it and hits him in the head with a hammer.

OK, maybe not everyone who's ever worked in customer service can relate, but you can see where we're coming from.

Wracked with guilt over the man's death, Lee considers turning himself in and even taking his own life until a news report reveals that his victim was actually a dangerous serial killer who arguably deserved everything he got.

That's just the start of it, though. A witness shows up, demanding money or she'll go to the police, which is far from ideal because a relentless detective named Jang Nan-gam is on the case, and he has no plans to let this go until the person behind the murder is brought to justice.

So begins a cat-and-mouse chase between Lee and Jang that takes you to some truly wild places that you'd genuinely never expect — that is, unless you've read the award-winning Naver webtoon the show is based on.

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To bring Kkomabi's darkly comic story to life, Netflix enlisted screenwriter Kim Da-min and director Lee Chang-Hee, a filmmaker best known for a movie named The Vanished, and an equally intense series called Hell is Other People.

Those projects are in good company with A Killer Paradox, which goes to some pretty dark places, too, as the body count begins to rack up.

Bloody, gory moments are interspersed throughout in a realistic manner, yet it's the more surreal, dream-like scenes that will chill viewers most.

Chang-Hee makes creative use of Lee's nightmares and hallucinations, alternating between disturbing imagery and sunny, well-lit daytime scenarios that reimagine each murder from our so-called hero's perspective.

These sequences in particular really stand out in a genre that's overcrowded with plenty of far less imaginative takes on murder, especially from a visual standpoint.

Narratively speaking, A Killer Paradox plays with genre, too, by shifting into another beast entirely at the halfway mark, four episodes in.

To say much more here would be to spoil quite how unhinged this show becomes, but just know that Lee's initial guilt over these seemingly random murders transforms into something else entirely, bringing elements of noir, comedy and even fantasy into what starts off as just a (somewhat unconventional) psychological thriller.

Twists like this live or die on the cast's ability to keep up and make us believe in the ride they've been asked to take us on. Thankfully, Woo-shik excels in the starring role of Lee, who's just as convincing as a student slacker as he is a tortured hero or hardened vigilante, no matter where Da-min's script takes him.

Following parts in Train to Busan, Okja and the Oscar-winning Parasite, A Killer Paradox will further cement Woo-shik's international career beyond his native Korean borders.

Lee's nemesis, Detective Nan-gam, is played by Son Suk-ku, who viewers might recognise from Netflix's Sense8, DP and Designated Survivor: 60 Days. His character is haunted by death as well, but in a very different way to Lee, and his charm plays well on the mirrored cat-and-mouse dynamic that serial killer stories like this love to channel.

However, it's Lee Hee-joon's Song Chon who threatens to steal the show when he turns up later with his own reasons for hunting down Lee. Seen most recently in Netflix's Badland Hunters, Chon plays a cocky, wildly unpredictable figure whose ties to the others create a whole new dynamic that brings some much-needed charisma to Killer's second half.

The way Song approaches death is darkly comic, and that's true of the show as a whole, which is punctuated throughout with moments that will make you gasp, but you'll also catch yourself laughing.

It's a lot to juggle, tonally speaking, and while this mish-mash does work for the most part, there are also some stretches which drag on as the script struggles to know where its focus should lie.

In that sense, A Killer Paradox is just as messy as the corpses that pile up around Lee, which is to the show's strength, but also its detriment.

A tighter focus and keener sense of the message behind this could have elevated the series more. But there's still tons of fun to be had when it comes to Killer's sheer ambition, not to mention the wish fulfilment of it all.

Because honestly, who hasn't wished revenge on someone who really deserves it? If you've worked in customer service, you'll know exactly what we mean, although we wouldn't recommend Lee's approach. That's for sure.

A Killer Paradox is streaming now on Netflix. Sign up for Netflix from £6.99 a month. Netflix is also available on Sky Glass and Virgin Media Stream.

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