As that sly dig at the Peter Jackson movie trilogy shows, Warchus clearly believes in the superior power of theatre to tell this sort of story, despite having directed on celluloid himself. He talks about theatre's 'poetic muscle', which lets it activate the imagination in a way cinema cannot and clearly relishes a project that encompasses lighting, choreography and special effects as well as dialogue.
Warchus's own pedigree is wide-ranging. His credits include opera, Yasmina Reza's Art and the Madness musical Our House. He even found time earlier this year to direct the farce Boeing Boeing. He's patently exhausted - he keeps on yawning - but far from enervated. 'Tolkien's is a great mind to spend four years with,' he says.
He's learned lessons from Toronto, streamlining the story and cutting 30 minutes off the running time. Yet he also knows that opening a big budget production in London raises the stakes. The Lord Of The Rings has to sell 75 per cent of its seats for nine months to break even. Nonetheless, he dismisses the notion that it's just a commercial venture.
'It's a genuinely soundly motivated thing,' he argues. 'Some people seem to view Lord Of The Rings as simply an exercise in making lots of money. I hope when they see it they realise that can't possibly be the case.'
'I don't just want to show people that we can stage Lord Of The Rings,' he goes on. 'I want to prove to them that we can make a great piece of theatre. If I can make this work as I imagine, then it will be an amazing opportunity and privilege to show people how amazing theatre can be.' As long as that pesky stage behaves, of course.
The Lord Of The Rings, in preview until Jun 19, runs until Mar 2008, Theatre Royal Drury Lane, Catherine Street WC2, Mon 7pm, Tue to Sat 7.30pm, Thu and Sat mats 2pm, £15 to £60. Tel: 0870 890 6002. www.thelordoftheringsthemusical.com Tube: Covent Garden