The creator of the BBC1 detective show starring Idris Elba has revealed that the third TV series will be the character's last before a film project

First the bad news: the next series of Luther will apparently be the last. Idris Elba will only get to brood and seeth and chronically overuse everyone's name for a few more hours, and then he'll be away from our screens forever.

And now for the good news: after the third series, creator Neil Cross plans to make a Luther movie. He told Radio 4's Front Row programme that "We'll wrap up Luther as a TV show, but I think we'll then probably make the leap to the big screen with John Luther."

Obviously, this is brilliant news. Often, when television programmes become films, it's cause for worry. Despite the runaway popularity of The Inbetweeners Movie, the idea of turning a show into a film still causes feelings of dread, fuelled by harrowing memories of Holiday On The Buses and Sex And The City 2 and the ongoing kerfuffle over the 24 movie. But Luther stands alone as a show that could feasibly become a decent film. In fact, it deserves to.

Luther has always been unashamedly cinematic. Its stories are already feature-length and – aside from the necessary cliffhangers written in to divide up episodes – have a beat pattern much more attuned to film than television. Take the first episode of the most recent series, for example. Its climax was a drawn-out sequence so unbelievably tense that it caused me to visibly age by about three decades. It was the stuff of first-rate horror movies, not down-at-heel BBC1 police dramas.

A movie would also suit Elba. His best work by some distance might be on the small screen, as either Luther or Stringer Bell, but he's nevertheless got the world of cinema in his sights. Although that ambition currently manifests itself in fairly disastrous work – either the lead in low-budget nonsense like Obsessed or tiny parts in brain-dead blockbusters like Thor or Ghost Rider 2 – that looks set to change. His profile will only rise after Prometheus is released, and then again after Guillermo del Toro's Pacific Rim next year, so hopefully the Luther film will hit just as he's reached the height of his stardom.

However, it's still some time away yet. So this is the perfect opportunity to offer some suggestions to Cross before he puts pen to paper. Personally, I wouldn't like to see the film wrap up too neatly. The end of series one was a gloriously unresolved knot of murder and revenge that, while frustrating, suited the story perfectly. In comparison, the end of series two – essentially Luther eating ice cream and smiling – felt a little glib. Luther doesn't suit closure. Seven is already a fairly obvious influence, so let's take it all the way. If there's going to be a film, let's make it as messy as possible.

Second, a Luther film wouldn't be a Luther film without Alice Morgan. As a character, Luther is never better than when he's caught up in her psychotic web. He's intrigued with her, he's appalled by her and he's possibly in love with her. She's leagues more interesting than last year's stage-school prostitute or that weird trash-talking Pam Ferris gangster – plus Ruth Wilson's star is on a similar ascent – so she desperately needs a spot alongside Luther on the big screen.

So does the thought of a Luther movie fill you with excitement or dread? And what would you like to see in the film? Leave your ideas below.