During a recent interview, the Sherlock star revealed that he went full method for the role, refusing to speak to co-star Kirsten Dunst the entire time they were on set together.
In the film Cumberbatch plays gruff cowboy Phil Burbank who has a strained relationship with his brother George's (Jesse Plemmons) wife Rose Gordon (Dunst).
Which is why, according to Cumberbatch, he chose not to speak to the star during filming, deciding instead to stay in character and adding that she did the same.