Editor’s note: To mark the release of the Warcraft movie we’re returning to our look behind the scenes of Duncan Jones’ epic, first published last year. Our review of the movie will be up on the site shortly.It’s the screaming you hear first. Starting at a low rumble, it gains in pitch until suddenly its source bursts through the wall of smoke. It feels like everything’s happening in slow motion; the villagers, their faces twisted in fear as they run through the muddy streets, slipping and falling in the twilight dim. Their pursuers; an army of twisted trolls, storming the Old Town quarter of Stormwind, cackling as they rip through the crowd, bouncing from victim to victim, sparing no-one from their savage attack. There – a troll grabs some poor blacksmith by the neck, and slams him into ground. There – a dressmaker is smashed in the face with a shield, leaving her to crumple like a rag doll. It’s a massacre. And then, the sound of hope – a clarion call sounds, and another army charges through the smoke. They glisten in suits of armour, wielding swords with four-foot blades and impossibly large shields. The leader, whose kit is…