Watch: Ian McKellen will play the Demon in West End's 'The Exorcist'

If a big budget West End stage version of seminal horror 'The Exorcist' just in time for Halloween didn't sound like enough of a treat, then things have been taken up a notch by the announcement that none other than Sir Ian McKellen will be be providing the voice of the Demon.

Astute observers may correctly guess that his performance as the creature that possesses young Regan is pre-recorded and he won't in fact appear on stage. But it's still a pretty spectacular piece of casting for one of the greatest voices in the biz.

Check out his terrifying tones in this fairly alarming new trailer.

'The Exorcist' is at the Phoenix Theatre. Oct 20-Mar 10 2018. Buy tickets HERE