Emily Blunt caused Cillian Murphy to "smash his head open" when they worked on 'Oppenheimer' together.
The 40-year-old actress stars as the wife of the wartime hero in the Oscar-nominated biopic that she was "very concerned" about how her co-star would sleep after taking on the mammoth role so decided to gift him with a luxury pillow, but when he awoke in the middle of the night and fluffed it, he missed it on the way back down and smashed his head off the bedside table.
She told The Sun on Sunday newspaper: "He’s going to kill me for telling this story.
“I was very concerned about Cillian’s sleep when we started shooting because I felt he had a monumental undertaking with this role.
"I thought, like, that’s a good start-of-shoot gift.
“He told me he woke up in the middle of the night and he was so thrilled to fluff himself back to sleep on the pillow, that he sort of threw his head down back on to it and smashed his head open on the bedside table.
“He was luxuriating in it so much he smashed his head open.
"So he came to set and they had to glue his head shut, all because of the pillow.”
The 'Devil Wears Prada' star noted that the former 'Peaky Blinders' actor - who has been nominated for an Academy Award for his role whilst she is also up for Best Supporting Actress - was an "amazing scene partner" and felt as if she was in a "masterclass" on set with him.
She said: "He was an amazing scene partner. I love Cillian, Mr Ocean Eyes, so much. He’s a wonderful friend.
"He’s captivating. He’s mesmerising in this role.
"Everything was such a masterclass watching him."