An unexpected circumstance can make any honest person do something unspeakable — like steal millions of dollars from one of the biggest fast-food companies in the world.

The crime becomes increasingly more complicated when colorful characters from Florida, the mob and a marketing agency all know a seemingly foolproof way to win $1 million from the ’90s McDonald’s Monopoly game.

Directors Brian Lazarte and Chicago-born James Lee Hernandez examine how an ex-police officer stole millions of dollars from the game over the course of 12 years in the six-part documentary “McMillions,” premiering Monday on HBO. The series, from a team of producers including Mark Wahlberg, explains how an FBI investigation unfolded over the course of a year only to be overshadowed by the events of Sept. 11, 2001.

“If your close friend or a family member came to you and said, ‘I have an ironclad way of winning a million dollars and nobody gets hurt,’ a lot of people would at least consider it,” said Lazarte.

Hernandez found out about the game fraud on a Reddit thread and shared it with Lazarte in 2012. “His first job was at McDonald’s,” Lazarte said, referring to Hernandez. It “sort of kicked off as a passion project.”

The filmmakers put in a Freedom of Information request with the U.S. government, and it took a little over three years before it was approved, said Lazarte. The project was meant to be a 90-minute movie, but “the more people that we spoke to about it, we realized, OK, this actually has the legs to get serious,” Hernandez said. “Because there is no way that we could fit all these characters into a single documentary.”

The six-part documentary introduces a variety of people involved in the scam and the FBI team that participated in the investigation. The fast-food fraud case had been lying around for a while by the time FBI special agent Doug Mathews picked it up. His attention led to a meeting with execs from McDonald’s, then based in west suburban Oak Brook.

Mathews created a fake video production crew to encourage the bogus “winners” to tell their story and enlisted Amy Murray, senior director of global marketing at McDonald’s. They were looking for a Monopoly mastermind who went by the name “Uncle Jerry.”

“Pulling back on a whole decade of lies, of course we wanted to know more about this,” Hernandez said. “Who didn’t want to win $1 million?”

The documentary will be accompanied by a “McMillions” podcast after each episode on HBO, Spotify and YouTube, where the directors talk about information they did not get to fit into the series.