10 Unbelievable Horror Movie Facts That Are Somehow True

Sissy Spacek standing in a blood-soaked dress as the titular character at her prom in Brian De Palma's Carrie is one of the most iconic visuals in horror history.

But it's also a moment that required more dedication than you likely realised.

When it came to that memorable prom scene, it wasn't simply a case of chucking some fake red stuff onto the actor once and moving on to the next part of the shoot. Nope, the sequence involving Carrie having pigs' blood dumped on her and going on a killing spree actually took days to complete.

So, rather than having new fake blood poured onto her at the start of each day and potentially messing up the continuity of the scene, Spacek reportedly had a better, quite unbelievable, idea.

As revealed by P.J. Soles (via Vulture), who appeared as Norma in the movie, the Carrie star actually slept in that blood for three nights. And when Soles remarked that her co-star was "amazing" for snoozing in "that sticky, icky stuff", Spacek was said to have replied by saying "no, it's gotta match, I want it to look great."

To say it looked "great" would be a bit of an understatement really, with that chaotic sequence eventually becoming an all-timer horror moment. 

Knowing just how committed Spacek was to consistently looking the part here just makes the whole thing even more captivating.