London (CM) - Emilia Clarke has revealed the details of a prank war with her Me Before You co-star Sam Claflin while they filming last year.

The 29 year old ‘Game of Thrones’ star is currently promoting the new movie, in which she is the co-star alongside fellow British actor Claflin (The Huntsman and The Hunger Games). Apparently, despite the sombre nature of the movie, the set also became the battleground of an escalating prank war.

“I put fish in his socks, but that was just one of them, the fish that we had for lunch,” Clarke told E! News about how bad it got. “I had limited resources. He had just pranked me and I was like, ‘I’ve got 20 minutes until the end of the day so I have to get this done’.”

Other practical jokes included Claflin hiding in a wardrobe in Clarke’s trailer for 20 minutes before jumping out, and a fart machine in Claflin’s wheelchair.

However, they never went too far and they both also had fun together on set. Claflin described going on a walk through a field outside London when they realised they were in danger of being chased by a herd of cows. “We ran and I carried Emilia on my back,” he said.