"Luther" is a TV rarity. A show beloved by fans the world over, it never overstays its welcome, and shows up just when you need it. Created and written by Neil Cross, "Luther" follows Detective Chief Inspector John Luther, an officer consumed with the weight of the crimes he investigates. Across the series, Luther and the other members of his unit, including Detective Sergeant Justin Ripley (Warren Brown), Detective Superintendent Martin Schenk (Dermot Crowley), and DS Benny Silver (Michael Smiley), take to the gritty streets of London and go up against the worst the city has to offer.

When "Luther" first aired in 2010, Idris Elba's star was on the rise. He had supporting roles in films like "28 Weeks Later," "Rocknrolla," and "American Gangster," and had received critical acclaim for his turn as Stringer Bell on "The Wire." Since then, Elba has become a bonafide international star, and DCI Luther is one of his most beloved characters. We may never see Elba bonded to a tuxedo and a particular martini order, but with "Luther" in his bag, who needs MI6?

Perhaps the best and worst thing about the BBC show is its perpetual disappearing act. As much as we would all love more DCI Luther on our screens, his absence has certainly made the heart grow fonder — it's also a testament to Elba's love for the character he continues to return for more. The first "Luther" film is scheduled to release in 2023 on Netflix and we can't wait, but until then, here is every season of "Luther" ranked from worst to best.

Season 3

As much as "Luther" is loved for its fresh take on the police procedural, there's no denying that the show rests on its own time-tested formulas (albeit with great success). Every season features one or two serial killers who Luther and company are tasked with taking down, usually within two episodes. There's also usually a subplot of a personal nature for Luther that stretches across the entire thing. However, even though this structure is repeated throughout the show's run, the stories told and the way they're resolved are exciting enough to excuse the set waypoints — season 3 being the exception to the rule.

Where the season comes up lacking isn't in its criminal endeavors. A fetishist copycat killer and a vigilante stretch Luther, Shenk, Benny, and Ripley thin, testing the team's wits and abilities at every turn. They're two exciting cases that left us on the edges of our seats. The season's missing link is the investigation against Luther conducted by DCI Erin Gray (Nikki Amuka-Bird), a former colleague of Luther's who disagrees with his methods.

The case built against Luther by Gray, DUS George Stark (David O'Hara), and an unwilling Ripley feels redundant and becomes more and more far-fetched as the season goes on. While season 3 is the only installment of the series that feels like a bit of a head scratcher story-wise, it says something about "Luther" as a whole that even its weakest season is still enjoyable.

Season 4

Season 4 begins with Luther living in isolation on the English seaside. The internal investigation against him is still being wrapped up, but when a cannibal serial killer shows up in London, Luther is called back to the city. The crimes are intriguing, grisly, and twisted, and the main cast continues their steadfast performances, upholding the chemistry established earlier in the show.

Where the series slightly stumbles is in its supporting cast and overstuffed plot lines. A post-"Game of Thrones" Rose Leslie joins the cast as DS Emma Lane, a young officer looking to avenge her partner's death, while Laura Haddock takes on the mysterious role of Megan Cantor, a young woman who lurks around Luther's seaside cottage and delivers news from the beyond. Unlike previous supporting characters, we aren't given enough time in the shortened season (just two episodes!) to build any real connection with Emma and Megan, making them forgettable and disposable.

The truncated runtime also shoulders much of the blame for why season 4's plot lines feel jumbled and bloated. Rather than trimming down the amount of story in a typical season, Cross (the season's sole credited writer) attempted to cram four episodes' worth of material into two. At the time, "Luther" fans such as myself were just happy to see Elba don the wool trench coat again, but on reflection, its excess failed to make any impact.

Season 5

Cross and Elba made us wait three years between seasons — factor in that season 4 was a measly two episodes, and that's basically a lifetime — but it sure was worth the wait. Season 5 felt like a return to form for "Luther," with old faces returning and compelling cases for DCI Luther to solve. A subplot involving George Cornelius (Patrick Malahide), an old adversary of Luther, ties the season together and introduces a larger world to the series.

DS Catherine Halliday (Wunmi Mosaku), a new young recruit, joins Luther, but unfortunately isn't given much character or depth (aside from being a bit naive), especially compared to the interesting textures DS Ripley received in earlier seasons. Even so, Halliday is a welcome addition to the show, nicely off-setting Luther's undercurrent of anger and bitterness.

The season's success ultimately rests on the arresting performance by Hermione Norris as Vivien Lake, a psychiatrist who's treating the season's assumed antagonist. Her performance is enhanced with a story that has many twists and turns, resulting in a thrilling season that both satiates our need for more "Luther" and also sets up some interesting threads to be explored in the future.

Season 2

Season 2 of "Luther" established the formula used across the rest of the series, with a single subplot that bridges the entire season and cases that span multiple episodes, a departure from season 1's more traditional episodic format. For the show's sophomore effort, a Punch-masked killer is inspired by a figure from Victorian-era folklore, going to horrifying lengths to emulate their hero. In addition, a man is murdering people at the whim of a pair of dice as part of a larger game. Both cases offer captivating mysteries, and watching Luther crack them (with Ripley's help) is fascinating.

The season-long personal subplot involves Jenny Jones (Aimee-Ffion Edwards), the young daughter of one of Luther's old acquaintances who is wrapped up in a prostitution and pornography ring. Tackling decidedly dark subject matter, Jenny's story is harrowing, disturbing, and heartwarming all at once. It's Jenny who makes Luther evolve into a character with genuine humanity, even more so than his estranged wife, Zoe (Indira Varma), did in season 1.

Where the first season had a great twist and reveal, season 2 of "Luther" elevated the show above "just" a police procedural. Here, the show became a distinct entry in a well-worn genre by exploring the moral grays of a detective's job and the complexities of Luther's moral compass.

Season 1

The opening moments of "Luther" perfectly encompass the title character, a man who has his reasons for flirting with codes and boundaries, often to someone else's peril. The show wastes no time in establishing our protagonist as something of an anti-hero, but one we will root for nonetheless.

The next moments show the brutality of Luther's job — a slain family and their dog lay in a bloody mess — and introduces us to Alice Morgan (the incredible Ruth Wilson), one of television's best psychopaths. Although Alice isn't a permanent fixture in the series, her presence is felt from episode 1 right through season 5's finale. Cross treats Alice with great sympathy and curiosity, which allows Wilson to develop her with a unique nuance not often seen in this type of character. And then there's the palpable chemistry between Elba and Wilson, which pushes the boundaries between cop and criminal.

As the longest season of the show (six whole episodes), season 1 gives us plenty of time to get to know Luther, his co-workers, and their relationships to one another. Each episode presents a new case for Luther, Ripley, and DCI Ian Reed (Steven Mackintosh) to solve, ranging from occult-influenced serial killers to war veterans. The season craftily mixes thrilling moments and explosive action sequences with Agatha Christie-like mysteries that build the tension to an unexpected boiling point by the season's end.

"Luther" is a crown jewel in Elba's sterling career and one of television's best shows, and it all started with a premiere season that bolts straight out of the gate and takes no prisoners.

Read this next: The 18 Best Crime Dramas In TV History

The post Every season of Luther ranked worst to best appeared first on /Film.