Warning: Spoilers ahead! Do not proceed unless you’ve watched “Crystal Lake.”

The “Friday the 13th” prequel series “Crystal Lake” finally reveals how the iconic horror villain Jason Voorhees is virtually indestructible and keeps coming back to life.

In the series — which is set in the ’70s and shows Jason’s mom Pamela on a killing spree after he allegedly drowns in a lake — it’s revealed that a shadowy entity was running experiments on him after he was born.

“I wanted to ground it in real-world things that were happening at the time,” the show’s creator Brad Caleb Kane exclusively told The Post. “When you’re talking about the ‘50s and ’60s, institutions were doing these things.”

One of the real-life examples Kane cited includes the 40-year Tuskegee study that ran between 1932 and 1972, where black men with syphilis were unknowingly studied and were not offered treatment for the disease, even when it was readily available.

He also cited Vanderbilt’s human radiation experiments in the ’40s, where pregnant women were unknowingly given radioactive cocktails or pills to track how the body absorbed iron during pregnancy. A study was later published that three of the children likely died due to radiation exposure, according to the Washington Post.

Kane added he really wanted to “lean into what was going on in the county at the time” for Pam and Jason’s backstory.

Viewers learn early on that Pam has a mysterious past when two men from a shadowy corporation show up.

It’s later revealed in a flashback that she was brought to a company by Jason’s father, Elias, while pregnant, where sinister scientists gave her drugs. After Jason was born, Elias then took his son to be experimented on.

As Elias explains on the show, scientists were experimenting on human subjects during the Cold War with the goal of giving them the qualities of a cockroach –  hoping they could engineer people who could survive a nuclear blast. 

After Pam discovers that Jason was being used as a lab rat, she brutally kills a scientist and escapes with her child. 

However, the experiments had lasting effects, making Jason so resilient to physical trauma that he returns stronger. 

To date, there’s been twelve installments in the “Friday the 13th” franchise, released from 1980 to 2009. 

In the movies, an adult Jason goes on a killing spree, wearing a hockey mask and wielding a machete. Every time he seems defeated, he returns. 

Pam also had her own killing spree in the original “Friday the 13th,” played by Betsy Palmer.

“Crystal Lake” explains that when Elias and his team of scientists gave Pam drugs during her pregnancy, the pills made her moods permanently unstable and volatile. 

“She puts her faith in science and her husband,” Kane told us. 

The  “Crystal Lake” showrunner noted that Pam “trusts them and she’s messed with,” similar to “The Stepford Wives” and the 1968 classic, “Rosemary’s Baby.” 

At the end of “Crystal Lake,” Jason returns from his supposed drowning with accelerated growth and is now an adult even though it’s only been a year since the drowning.

He’s seen wearing a burlap sack over his head, which is what he originally wore in the first two “Friday the 13th” movies before 1982’s “Friday the 13th Part III” introduced the iconic hockey mask. 

Kane said that if “Crystal Lake” continues, he’s “not sure if we’ll get to the hockey mask, unless we do flash-forwards.”

He noted that “Crystal Lake” is focused on Pam, and she’s dead by the time the hockey mask shows up. 

“There is a universe where we do flash-forwards and show the hockey masks,” he teased. “I just don’t know what it is yet – because this is, at its heart, a Pamela Voorhees show.” 

Referring to Jason’s burlap sack mask, he said, “We do have another famous mask in the show. And now that we know that Jason is out there in that mask, there are more stories to tell with that.” 

“Crystal Lake” is now streaming on Peacock.