Sometimes big adventures begin with an unfortunate accident.
For Jack, in a new movie remake of the classic tale, the accident is trading his uncle's horse for the promise of magic beans, and letting one take root under his home. Cue beanstalk. Home and princess love-interest hurtle into the sky, and bumbling Jack, star-on-the-rise Nicholas Hoult, must find his inner hero fighting an army of giants. For Hoult, the accident was less fantastical and more meteorological: a lot of rain in Australia.
Hoult, who most would know as the dorky kid in the movie About a Boy, or cocksure teen charmer in TV series Skins, was all set to take the next step on his skyrocketing career playing Nux in George Miller's return to the Mad Max series: Fury Road. But heavy rain turned the bleak, post-apocalyptic desert in Broken Hill to a pleasant flower-strewn meadow, and the shoot was put on hold (it eventually filmed in 2012 in the Namibian desert).
Nicholas Hoult with Eleanor Tomlinson in a scene from the film.
So Hoult was at a loose end, and recalled a chat with director Bryan Singer while they were working on X-Men: First Class.
''He mentioned he was making [Jack the Giant Slayer] and he'd been working on it for quite a while, making sure how he was going to motion-capture the giants and it sounded like an interesting project.
''I really enjoyed the script and I liked that Jack was a very unlikely hero.
Giant undertaking: Nicholas Hoult plays the title character in Jack the Giant Slayer.
''It's definitely interesting trying to play different characters and people you find interesting and you understand. But also, if you get the chance to ride around on horses and do big action sequences and fight imaginary giants - it's what I played at growing up in the garden.''
Hoult has done a lot of growing up recently. It's hard to reconcile this blue-eyed, charming 23-year-old lad with the shuffling 11-year-old who squeaked his way through Killing Me Softly with His Song in the excruciating climax of About a Boy.
In 2010, he was dubbed one of Variety's ''10 actors to watch'', and inspires gossip headlines such as ''5 reasons why hunk Nicholas Hoult should be your next cinematic crush'', thanks to appearances in 2009's A Single Man, 2011's X-Men and 2013's Warm Bodies, a quirky zombie version of Romeo and Juliet. Despite his turn in Warm Bodies, Hoult says he isn't deliberately going for romantic leads. ''Sometimes I think [romantic movies] can become quite stagnant and stereotypical, and sometimes the roles just aren't very interesting. It's more about mixing it up in terms of very different genres and characters.''
To prepare to play Jack, Hoult trained at horse riding and exercised his beanstalk-climbing muscles.
''We're firing crossbows, zip-lining across huge divides, swinging from vines and dodging flaming trees that the giants uproot and hurl at us,'' he says of the action.
The filmmakers said they chose Hoult because they wanted someone the audience could identify with - an everyman, not a superhero. The beanstalk, after all, is a metaphor for growing up and facing your fears.
Hoult says that, on Singer's advice, he took his cue from movies such as The Princess Bride: ''As scary as it could be and as intense and action-packed, there's also a humour about it and a lightness.''
Jack was shot around the English countryside, reflecting the centuries-old origins of the original fairytale (in one of its oldest forms it was part of the King Arthur legend). But a lot of it was created in digital 3D - most obviously the giants: ugly, angry, eight-metre-tall warriors.
Hoult says he was ''pleasantly surprised'' by the personalities and performances of the giants (one of which is voiced by Bill Nighy) when he saw them for the first time, months after shooting. ''It's always difficult,'' he says. ''You've got an image in your head, you've been shown rough pictures and you can hear the actor's performance coming over a loudspeaker. In the end, hopefully it matches up to what's going on.''
Work keeps flooding in for Hoult: the next X-Men film, an adaptation of Sebastian Faulks' wartime novel Birdsong, and a futuristic thriller called Young Ones.
''There's no grand plan,'' Hoult says. ''It's just see what's about and try and work with good people.''
With, hopefully, the odd lucky accident on the way.
Jack the Giant Slayer
Genre Family adventure.
Director Bryan Singer.
Stars Nicholas Hoult, Ewan McGregor, Stanley Tucci, Eleanor Tomlinson, Bill Nighy.
Critical buzz Mixed reviews, with CNN perhaps summing it up: ''Slight, but consistently amusing.''
Release March 21.