You’ll keep coming back to the sketch: a thin face and thinning hair, a suit, a pair of sunglasses, a tabula rasa of a forehead. The problem with the FBI’s best idea of what D.B. Cooper looked like is that it looks like a generic composite of Average White American Man in 1971. According to the FBI poster: Age? Mid 40s. Build? “Average.” Hair? “Normal style.” Voice? “No particular accent.” Clothes? “Black suit, white shirt, narrow black tie.” In fact, when one of the agents working the case sent the sketch to his mother, she figured it was her son.

That blankness is at the center of The Mystery of D.B. Cooper, a new HBO documentary, which premieres on November 25, 49 years after someone known as Cooper, on the day before Thanksgiving, boarded a plane in Portland, Oregon. He ordered a bourbon and soda, then handed the stewardess a note: “Miss, you’re being hijacked. I’ve got a bomb. Come sit next to me,” Tina Mucklow, that stewardess, recalls. When she did, he showed her a briefcase with filled with dynamite, wire, and a battery. He had her light his cigarettes. He demanded four parachutes and $200,000 in cash. The plane landed in Seattle. The passengers got off. Then it took flight again, with only Cooper, Mucklow, and the pilots. At 10,000 feet, near Ariel, Washington—a small town about 32 miles north of Portland—Cooper jumped in the rain, at night. In 1980, a boy found $5,800 of the money buried along the Columbia River. Cooper and the parachute have never been found, and the case remains the only unsolved airplane hijacking in U.S. history.

But holy hell have people been trying to solve it. The FBI finally closed the case in 2016, after 45 years. Others have kept after it. The Mystery of D.B. Cooper tells the story of the crime, via interviews with those involved (like Mucklow) and reenactments. It intercuts this story with those of obsessive hobbyists, like a Vietnam vet who walks the woods where Cooper supposedly landed each day, seeking the parachute. And it runs down the stories of four suspects in the case and lets you weigh the narratives and evidence yourself. This is, for viewers, much of the thrill. As presented in the documentary, each of the four suspects is decently compelling, and each has some sleuthy person convinced they’ve got the real Cooper.

Take, for instance, suspect number one, Duane Weber, who told his wife Jo that he was Cooper on his death bed in 1995. She then discovered his fake IDs, that he’d bought a couple cars after the crime. With the help of another Cooper obsessive who helps her “put her memories in order,” she recalled a trip to Washington State in 1979, during which Weber mentioned a spot where Cooper walked out of the woods.

Ultimately the story expands to show that there have been hundreds of people convinced their relatives or acquaintances are Cooper. Within five years of the hijacking, the FBI had considered over 800 suspects. The documentary aims to become about people’s “need to believe,” about mystery and faith and America’s love of maverick banditry myths like Jesse James and Bonnie and Clyde. It elides some details that’d cast greater doubt on its suspects, like DNA recovered from a clip-on tie left in Cooper's seat. That isn't a big deal, since Cooper is very likely dead—either from the jump, or time—and solving the case would solve little. But as a look into mass cultural obsession, the documentary would’ve done better to focus on one person’s fixation, really exploring what director John Dower calls the "D.B. Cooper–shaped hole" in his subjects. Like these people, the film is too fixated on the who, on the evidence, and not enough on why people can't let this go. Instead it plays the four narratives against each other for a little frictional drama. 

That makes for a decent heist whodunit, though, good for a Thanksgiving watch, especially in a year in which your relatives need only a Zoom call as alibi. Because that guy in the sketch? He could pass for my uncle.