Butcher Block is a weekly series celebrating horror’s most extreme films and the minds behind them. Dedicated to graphic gore and splatter, each week will explore the dark, the disturbed, and the depraved in horror, and the blood and guts involved. For the films that use special effects of gore as an art form, and the fans that revel in the carnage, this series is for you.

Three years before Eli Roth helped usher in the subgenre of horror dubbed “torture porn” with Hostel came his gory feature debut, Cabin Fever. For the group of five college graduate friends that embarked on a weekend getaway trip to a cabin in the woods, it wasn’t a demonic presence or masked maniac they had to contend with, but one gnarly virus that quickly escalates from minor skin rash to widespread aggressive decay. It also happens to be extremely contagious. The terrifying disease has catastrophic ramifications for the group in every possible way, from the physical to the social and psychological.

Roth wrote the script at age 22, while still in film school, based on his own gruesome experience with a mysterious skin infection at age 19 that left his skin coming off in bloody chunks when he scratched at it or shaved. Merging this life experience with a formative horror film, The Evil Dead, sparked the idea behind Cabin Fever. He gave an early draft to his college roommate expecting to terrify him, but he was perplexed to hear his roommate laughing instead. That roommate, Randy Pearlstein, wound up co-writing the script with Roth to deliver both scares and laughs.

The road to getting Cabin Fever made proved much more arduous and long. It took six years for Roth to find producers willing to take on what would be a sure R-rated bet. When he finally secured investors, the 2001 anthrax attacks featured prominently in the news made one of the film’s investors get cold feet and pull out of the project a mere 3 days into production. It was only the beginning of the constant financial struggle, often causing halts in production that would last months while Roth and team attempted to scrounge up more funds to continue.

Perhaps the biggest stroke of luck came from Roth’s previous working relationship with David Lynch, with whom he’d met while working on his NYU thesis film and handled research for a project of Lynch and composer Angelo Badalamenti. It was through Lynch that Roth landed the expert special makeup effects studio KNB EFX Group to handle the gore, rotting flesh, and free-flowing blood effects for Cabin Fever. With the core trio of Howard Berger, Robert Kurtzman, and Greg Nicotero as special makeup effects supervisors, and Garrett Immel as a key artist, it’s the gooey, grisly practical effects that elevated Cabin Fever into memorable horror that holds up over a decade later. The low budget meant that KNB EFX had to get creative with the makeup effects, and likely provided great experience with working on visceral gore on a small scale that would later come in handy when working on The Walking Dead.

After premiering at the Toronto International Film Festival, Cabin Fever sparked a bidding war from investors, including some that’d previously passed on the film pre-production, and went on to become the highest grossing film released by Lionsgate in 2003. All of this to say that while Cabin Fever came before the “Torture Porn” craze, its success proved that R-rated horror could sell, and sell well. It helped pave the way for the brutal wave of horror that emerged in the early aughts.

Cabin Fever takes the cabin in the woods subgenre of horror and gives it an unflinching body horror twist. There are few things as more horrifying as being a stranger in your own skin, especially when it involves a disease that rapidly progresses from benign rash to oozing ulcers to necrotic tissue sloughing off with the barest of touch, all in the span of hours. The concept alone can induce nightmares, but thanks to the uncanny talents of KNB EFX Group, these nightmares were brought to life in a visually traumatic way.