With characters like Sherlock Holmes and Dr Strange under his belt, he's signed up to play a supposed 41-year-old who is really 400.
He'll star as Tom Hazard in the film adaptation of the forthcoming How to Stop Time by author Matt Haig.
Described as a "wildly imagined love story", it follows Haig's children's books such as A Boy Called Christmas.
How to Stop Time won't hit shelves until July, but we know Hazard's youthful looks are down to an "extremely rare condition".
"The prospect of Benedict Cumberbatch playing Tom Hazard is a hugely exciting one and I could not be happier," Haig said.
The writer is best known for his quirky - and dark - stories about family life.
Cumberbatch's production company SunnyMarch will make the film with Studiocanal, while the actor will also take on the role of executive producer.
Before that, he'll be coming back as the eccentric surgeon Dr Stephen Strange in the Marvel superhero movies Thor: Ragnarok and  Avengers: Infinity War.
He'll also star in The Current War as the real-life genius inventor Thomas Edison.
Follow us on Facebook, on Twitter @BBCNewsEnts, or on Instagram at bbcnewsents. If you have a story suggestion email entertainment.news@bbc.co.uk.

The Egyptian, 25, has signed a five-year deal and has been a prime target for manager Jurgen Klopp.
At current exchange rates, the fee is short of the club record £35m paid for Andy Carroll in 2011 but matches the sum they spent in 2016 to make Sadio Mane the most expensive African player.
Salah almost joined Liverpool from Basle in 2014 before moving to Chelsea.
Liverpool boss Jurgen Klopp said Salah has "the perfect mix of experience and potential", adding: "This is a really exciting signing for us.
"I have followed him since he emerged at Basle and he has matured into a really good player.
"His pace is incredible, he gives us more attacking threat and we are already strong in this area. I like that we will make it even more competitive."
Salah will wear the number 11 shirt, with Roberto Firmino moving to number nine.
After only six Premier League starts following his £11m move, Salah had loan spells at Fiorentina and Roma before joining the latter in a permanent move for about £15m last summer.
He was a key figure as Roma finished second in Serie A last season, scoring 15 goals in 31 league appearances.
Liverpool have already signed Chelsea's 19-year-old striker Dominic Solanke, who was top scorer as England won the Under-20 World Cup and will join on 1 July.
That fee will be decided by a tribunal after he rejected a new contract at Stamford Bridge, with the fee expected to be about £3m.
Benedict Cumberbatch's versatility shows no end as he gears up for another offbeat role.
[NEXT_CONCEPT]
Liverpool have completed the 39m euro (£34m) signing of Roma's former Chelsea winger Mohamed Salah.