HBO launched its documentary series “McMillions” at the Sundance Film Festival last month, pulling back the curtain on how a man defrauded $24 million by gaming McDonald’s Monopoly sweepstakes between 1989 and 2001. The series features interviews with subjects from both sides of the law, but co-director Brian Lazarte stumbled upon the thread before meeting anybody who was involved with the grift.

“It started in 2012. I was laying in bed, cruising through Reddit when I saw a TIL. Today I learned nobody ever won a McDonald’s Monopoly game,” co-director Brian Lazarte told Variety at the Sundance film festival, presented by AT&T.  “I was obsessed with the game as a kid [and] my first job ever was at McDonald’s when I turned 16.”

Co-director James Lee Hernandez also explained the ongoing waves of disbelief he went through while making the series.

“For anyone who grew up in the ’90s and remembers playing that game, there’s nostalgia to the story,” Hernandez said. To discover the whole thing was rigged, it’s like pulling back the curtain on something we really believed was true for well over 10 years.”

“We really designed the series to mimic our surprise, Lazarte said. “The twists and turns that it takes, we lived that when we were learning all this info or talking to these people.”

“McMillions” is currently airing on Mondays at 10 p.m. on HBO.