Hollywood loves a fallen hero. From Christian Bale’s broken Batman in The Dark Knight Rises to Daniel Craig’s wasted James Bond in Skyfall, there is something about the sight of a once-titanic figure laid low that inspires and enthuses film-makers.

As our heroes drink themselves into oblivion, or drown in self-pity, we are reminded of the contrast with their better, truer former selves. The stage is set, inevitably, for sudden and radical rehabilitation – why allow Bane to break Batman’s back if not to allow Gotham’s dark knight the sweetest of subsequent revenge? Why show 007 so ravaged by drink that he cannot hold his Walther PPK, unless it is merely a blip on a predictable path back to insouciant business as usual?

Ever since the debut teaser for Star Wars: The Last Jedi hit the web back in April, there have been hints that Rian Johnson is trying something similar with Mark Hamill’s Luke Skywalker in the forthcoming space opera sequel. Here we have the untouchable hero of the original Star Wars trilogy, the guy who introduced most of us to the concept of magic space priests and dinky laser swords in the first place, warning that he knows “only one truth – it is time for the Jedi to end”.

This week’s issue of Entertainment Weekly confirms suspicions that Johnson is determined to reinvent Luke as something of a sad sack in the new instalment. Daisy Ridley, whose Force-sensitive scavenger Rey was last seen handing a lightsaber to a disbelieving Skywalker at the end of 2015’s The Force Awakens, describes the Jedi master as a “grumpy guy on an island who doesn’t want me here,” while the magazine itself warns that the Luke is a “broken man” who “would have preferred to stay lost”.

Hamill himself is not without his reservations about this tricky character arc. “The fact that Luke says, ‘I only know one truth. It’s time for the Jedi to end…’ I mean, that’s a pretty amazing statement for someone who was the symbol of hope and optimism in the original films,” he tells EW, adding: “When I first read it, my jaw dropped. What would make someone that alienated from his original convictions? That’s not something that you can just make up in an afternoon, and I really struggled with this thing.”

It’s up to you Rey … she’d better remedy the situation. Photograph: Youtube

It’s not hard to imagine where Johnson is going with all this. Star Wars fans are desperate to see Luke back in action, taking up his rightful place at the heart of the Resistance alongside Leia, Oscar Isaac’s Poe Dameron, Rey, Finn et al. However, it can’t be as simple as just turning up on Ahch-To and speeding away five minutes later with Luke in his rightful place on board the Millennium Falcon, reminiscing about the time Vader chopped his hand off and losing at monster holo-chess to Chewbacca. A deeper understanding of Skywalker’s journey into misery is required if we are to believe that he’s capable of getting back on his feet and blowing up a Death Star or two.

We have a fairly good idea why Luke exiled himself on Ahch-To in the first place: Kylo Ren, who Hamill suggests Skywalker believed was a new “chosen one”, murdered his mentor’s trainees and flounced off to join the Dark Side. Yet this is Luke Skywalker we are talking about, who witnessed his own surrogate parents burnt to a crisp at the outset of 1977’s Star Wars and barely blinked an eye. There must be something more here to Skywalker’s descent into despair.

Why did Luke fail to go after Ren; to put right his mistake? As the more experienced Jedi, it might be that he is the only being in the galaxy capable of taking down the whingey Vader wannabe.

Kylo Ren … why didn’t Luke go after him? Photograph: Allstar/Disney/Lucasfilm

It seems likely that there is some connection here to Skywalker’s loss of faith. Is Luke blaming his own inability to spot Ren’s true nature on some fundamental glitch in his own training, or even some basic flaw in the makeup of the Jedi order itself? Might this discovery reveal why Yoda and the Jedi council failed to spot that Anakin was a wrong’un in the god-awful prequels, despite the young padawan’s moody emo tendencies and penchant for cold-blooded massacre making it rather obvious to the rest of us that he wasn’t exactly space priest material?

Even if Luke has decided the Jedi faith needs its own religious restructuring before the First Order can be defeated, why has he not begun the process of setting about that work? Instead, he seems content to sit on a rock and mope beside a bunch of birds and alien nuns (it turns out the Porgs are not Ahch-To’s only indigenous species). Hope has always been the catalyst for change in Star Wars, yet it seems that the saga’s greatest emblem of faith in a better future is currently completely bereft of it.

This, it seems, is the mystery that Rey will be charged with unravelling. Until she does, we’ll be stuck with a version of Luke that nobody ever asked for, let alone expected to receive. Let’s hope our young hero gets to the bottom of the Jedi master’s funk as quickly as possible. There’s nothing wrong with challenging an iconic character in radical new ways. But this all-new, all-grumpy Jedi-hating version of Luke Skywalker could get pretty old, pretty quickly if he’s allowed to hang around too long.