Sir Ian McKellen has joined the cast of The Exorcist stage production coming to the West End later this month. The legendary stage and screen actor will feature as the voice of the demon in the production, which will arrive at the Phoenix Theatre in London from October 20th. The uniquely theatrical experience is directed by Sean Mathias and adapted by John Pielmeier.

Widely considered the scariest movie of all time, the film adaptation of The Exorcist sparked unprecedented worldwide controversy when it was released in cinemas in 1973. Winner of two Academy Awards, William Friedkin’s masterpiece saw audiences petrified to the point of passing out and went on to become one of the top ten highest grossing films of all time.

Here’s the official synopsis for the new production:

“Oh please, Mother, make it stop!”

When the medical profession fails to provide answers to young Regan’s strange symptoms her desperate mother Chris turns to a local priest for help. But before Father Damien can tackle what’s before him, he must overcome his own shaken beliefs, as this fight is for more than just one girl’s soul…

“I’m telling you that ‘thing’ upstairs isn’t my daughter…”

As previously announced, Jenny Seagrove will play Chris MacNeil opposite Peter Bowles as Father Lankester Merrin, Adam Garcia as Father Damien Karras, Todd Boyce as Doctor Strong, Elliot Harper as Father Joe, Isla Lindsay as Sharon, Mitchell Mullen as Doctor Klein, Tristram Wymark as Burke and Clare Louise Connolly as Regan.

The Exorcist will arrive at the Phoenix Theatre on October 20th. Check out the trailer below.