Sherlock is headed back to the big screen with a big name actor: Ian McKellen will star as the classic detective but in a retired form.

Director Bill Condon has teamed up with his Gods And Monsters star Ian McKellen for A Slight Trick Of The Mind. “McKellen will play a retired Sherlock Holmes who is haunted by a 50-year-old unsolved case,” according to Deadline. Based on a novel by Mitch Cullin, the screenplay is adapted by Jeffrey Hatcher (The Duchess).

The synopsis for the book A Slight Trick Of The Mind follows:

It is 1947, and the long-retired Sherlock Holmes, now 93, lives in a remote Sussex farmhouse with his housekeeper and her young son. He tends to his bees, writes in his journal, and grapples with the diminishing powers of his mind. But in the twilight of his life, as people continue to look to him for answers, Holmes revisits a case that may provide him with answers of his own to questions he didn’t even know he was asking–about life, about love, and about the limits of the mind’s ability to know. A novel of exceptional grace and literary sensitivity, A Slight Trick of the Mind is a brilliant imagining of our greatest fictional detective and a stunning inquiry into the mysteries of human connection.

You can order the book on Amazon. It has a 4 1/2 star review at the online retailer’s website.

Shooting on the film will begin in the U.K. next April. Condon is currently in Toronto where he’ll premiere The Fifth Estate, his Wikileaks moving starring Benedict Cumberbatch as Julian Assange.

McKellen is best known for his role as Gandalf in The Lord of the Rings and The Hobbit trilogies. The latter will release The Desolation of Smaug (Part 2) this December.

In our opinion, McKellen is one of very few actors that the internet – primary BBC Sherlock fans – would approve of playing the classic role while Benedict Cumberbatch still stars as the character in the television drama.

Thanks, Deadline.