The Meaning Behind Mindhunter Season 2's Haunting BTK Killer Finale Scene

In the world of Mindhunter, behavior rarely gets better. A murderer becomes a serial killer. A handful of murders become dozens of slayings. A rocky relationship turns into an expired one. However, Mindhunter season 2 tries to convince us its most fearsome looming figure, the “ADT serviceman” better known as Dennis Rader/the BTK Killer (Sonny Valicenti), may just stop his reign of terror.

Then you get to the final scene of Mindhunter 2019’s finale, “Episode 9.” With just one minute of screen time, the Netflix thriller promises us the BTK Killer is poised to become an even more dangerous entity in a possible third season. It's a fact that becomes increasingly chilling the longer you look at the clues in front of you.

In a vacuum, Dennis’ last moment of season 2 is already a nightmare fodder. We first see the serial killer standing in a motel bathroom alone. He is wearing a slip, a watch (which he likely stole off of his “Episode 2”-mentioned first kill), and the most soulless plastic mask known to man. Dennis walks around a standing camera and past a bed. The mattress is laden with trophies from his victims, whom he famously bound, tortured, and killed. We can see costume jewelry, hair ties, religious chains, shoes, undergarments, and ID cards, along with the news stories reporting each woman’s death. There are highly sexual bondage photos of Nancy Fox and Shirley Vian, real-life BTK victims, in their respective piles.

Then things get explicitly sexual. Dennis picks up a rope tied to a doorknob and we realize one of the ends is fashioned into a noose. Dennis puts the rope around his neck and violently jerks forward, choking himself. This is an instance of autoerotic asphyxiation, a kink of Dennis’ we saw in the second season premiere, “Episode 1.” With that harsh image seared into our minds, Mindhunter smash cuts to black with Peter Gabriel's 1980 song “Intruder” playing over the credits.

It’s that callback to “Episode 1” — that reminder of Dennis’ masochistic sexual preferences — that should really concern us looking into Mindhunter's future. The macabre visuals in Dennis’ motel room are just the window dressing.

The season begins with Dennis’ wife Joanne (Katherine Banks) finding her husband in a very similar masturbatory setup in their home — all that’s missing are the souvenirs. Joanne is shocked and runs out of the house. Dennis is immediately embarrassed. We watch Dennis’ attempt to squelch his compulsions in subsequent cold opens. First, he sleeps on the couch and considers the book Joanne hands him, Therapeutic Approaches to Sexual Deviancy. In “Episode 3” he goes to the library to indulge his torture fantasies with drawings rather than acting them out. By “Episode 5,” Dennis is burying his beloved serial killer paraphernalia in the Rader backyard, down to his frightening mask.

We’re left knowing he didn’t dig nearly a large enough hole to keep grizzly desires as dark as his buried. But, we can hope, right?

“Episode 8” tells us there is no hope. While out on an ADT service drive, Dennis stops and stares at a woman unloading groceries in front of her home in Eastborough, KS. Dennis' wedding ring is obvious in the shot, reminding you of the better angels in his life. Dennis drives off, but “Episode 9” confirms that Eastborough moment rekindled his desire to feed his compulsions. The mask has been dug up. He’s back to choking himself to get off. And, the many reminders of Dennis' victims have been brought into his ritualistic sex play, which is something he didn’t even need at the start of the season. This tableau all but screams, “Dennis Rader, serial killer, is fully back into action.”

That means we should expect to see Dennis return to his murderous ways in a prospective Mindhunter season 3. This turn would make sense considering the drama’s penchant for making small time jumps between seasons. While most of season 1 takes place in 1977, season 2 is mostly set in 1980.

If season 3 is set in the mid-1980s, there are a number of BTK crimes the series could cover. 1985 and 1986 both suffered murders now attributed to Rader. The 1985 victim, Marine Hedge, lived just down the street from Rader. A shot of the serial killer watching a Hedge-like fictional avatar from his window would be pure, unadulterated Mindhunter. In 1988, the wife of a murder victim also received a letter whose author claimed to be BTK, but experts disagree on the validity of that statement according to local newspaper The Witchia Eagle.

If the series decides to go past the '80s, Mindhunter could also tackle Rader’s last substantiated murder — the 1991 slaying of Dolores Davis — or his 2005 arrest.

It appears no matter where Mindhunter goes, the brutality of the BTK Killer will be there. Season 2 was just the calm before a new and terrible storm — and that motel room scene was the first strike of lightening.