Kit Harington's Spooks injury
Kit Harington "lost consciousness" while filming 'Spooks: The Greater Good'.
The 28-year-old actor was accidentally thrown through a wall while shooting the spy saga and was left in agony by the error, but movie producers were so impressed by the subsequent footage, they decided to keep it in the finished film.
He said: "I wasn't meant to go through that wall. That was a mistake.
"It worked brilliantly on film but it hurt like hell.
"That was me. I've still got the bump on the head to prove it.
"If you slow it right down you can see me lose consciousness for a second."
While producers were pleased with the footage, the incident initially caused panic on set.
Kit added to The Sun newspaper: "It was halfway through the film. After the initial panic everyone went: 'Great shot!'
"But at first it was a bit worrying -- you might have killed your lead actor."
Despite the accident, the 'Game of Thrones' star hasn't been put off doing his own stunts because he enjoys action scenes so much.
He explained: "I really love it. I've said it before, but you can lose yourself in an action scene in a way that's much easier than to lose yourself in a dialogue bit.
"I really enjoy the physical aspect to my work and this gave me the opportunity to do that in a different setting from what I am used to."