"13 Hours: The Secret Soldiers of Benghazi" comes out Friday in the United States, and it's sure to prove controversial. The Paramount Pictures movie, which stars James Badge Dale and John Krasinski, centers around the Sept. 11, 2012 terrorist attack on the diplomatic compound in Benghazi, Libya, that left four Americans dead.

Benghazi, as the incident has been nicknamed, came under immediate investigation when people raised questions about what caused it, how it could have been stopped and whether the White House misled Americans afterward. One of the probes uncovered the use of a private email address by Hillary Clinton, the secretary of state at the time and now a front-runner for the Democratic presidential nomination.

The release of "13 Hours" — about 10 months away from the 2016 election — has already inspired debate over what really happened. Here's what you should know:

1. The film is based on a book titled "13 Hours: The Inside Account of What Really Happened in Benghazi," which was released in 2013 by Mitchell Zuckoff. It was written from the accounts of five CIA contractors who lived through the fight in Benghazi. "What the five survivors have to say is at once compelling and enthralling, infuriating and heartbreaking," the Wall Street Journal wrote in its book review.

2. One of those operators, Kris Paronto, has indicated on social media that he supports the film. He wrote on Twitter that "13 Hours" was "a real war movie" and attended the red carpet premiere.

3. The movie includes the CIA contractors' statements that they were ordered to stand down once they learned of the attack while at their nearby annex. TIME reported that although there is evidence that the security team was told to wait, "there is no evidence of a 'stand down' order." Democratic lawmakers have supported this fact, but Paronto told Politico they're wrong. 

“There is no sensationalism in that: We were told to ‘stand down,’” he said. “Those words were used verbatim — 100 percent. … If the truth of it affects someone’s political career? Well, I’m sorry. It happens."

In the movie — and real life — the operators took action when at 9:40 p.m. that night, gunmen began attacking the compound, where U.S. Ambassador Chris Stevens was visiting. The team left about 20 minutes later.

4. They tried to rescue Stevens and State Department information management officer Sean Smith, both of whom later died from smoke inhalation. Later that night, at about 4 a.m., the CIA annex came under attack. The contractors "spent the tense night staring from the roof through night-vision goggles, while the two dozen or so CIA and diplomatic personnel they were guarding huddled in buildings below," according to the Washington Post.

5. Two Navy SEALs died at the annex: Tyrone “Ty” Woods and Glen Doherty.

6. The Obama administration gave varying accounts of what happened. First, the president told reporters the attack was the result of anti-Islamic YouTube video that sparked protests. But the next day, Obama called it "an act of terror."

Later reports also revealed the Americans may have had advanced notice of the attack and ignored warnings to retreat. 

7. Ahmed Abu Khattala, the suspected organizer of the attack, was captured in June. He is awaiting trial.

The Wall Street Journal wrote about the doubts involved with the film. "How much of this is true (surely the team’s individual and collective heroism), how much is subject to dispute (the stand-down order will rank high on that list) and how much is dramatic license?" it reported. "A movie review isn’t the place to sort that out, any more than a multiplex is a place to study history."