‘Stranger Things 3, Chapter 4: The Sauna Test’ – recap, easter eggs, theories, references and more


Oh, sweet clarity. In the recap of the last episode, we spoke of the disparate threads of plot in this stunning third season of the hit Netflix show. In Chapter 4, much is made clear in a pivotal scene in which the gang gets back together and Will comes clean about his recent sensations. He tells his pals that he thinks the Mind Flayer is still present, reasoning:

– In Stranger Things 2, part of the Mind Flayer entered his body

– His mother, Joyce, forced it out of him


– Eleven closed the portal and trapped most of the Mind Flayer in the Upside Down

– But some remained

– That part of the Mind Flayer needs a new host – and has likely found one

–That host is likely to be Billy, Max’s brother, who’s been acting hella weird.

The episode plays out in four separate but linked missions, all of which shine light on the wider plot.  

The four missions

Joyce and Hopper – investigating the source of power outages in Southeast Hawkins

Joyce and Hopper – a Cagney and Lacey for a new generation – discover via some, er, torture (more later) that the owners of Starcourt have been exploiting Mayor Kline and buying up property in the south east of Hawkins. Joyce speculates that, while they were looking to the lab as the source of the magnetic messing-around, it may actually have come from one of these properties in the possession of Starcourt, so they set out to explore them. 

Dustin, Robin, Steve and Erica – investigating the Starcourt loading bay frequented by Russians


Having decoded the Russian message, the Scoops Ahoy crew have figured out that something screwy is going on at the mall, albeit behind a locked loading bay door. Robin acquires the blueprints and figures out a (risky) way in.

Will, Mike, Eleven, Max and Lucas – trying to figure out if Billy is host to the Mind Flayer

This is the sauna of the title. They figure if they can trap Billy in the swimming pool changing rooms an crank up the heat, the Mind Flayer will reveal itself. 

Stranger Things

Nancy with or without Jonathan – investigating the rats, and the truth about Mrs Driscoll

Sacked from the paper, Nancy chases Mrs Driscoll’s story, heading to the hospital to figure out why she’s become a goo-mouthed zombie. 

The talking points

Corruption is rife in Hawkins – on the newspaper and in City Hall 

Nancy and Jonathan are sacked by editor Tom, Heather’s dad, who is now sweaty and bloody and showing all the signs of a flayed mind – for chasing the story about the rats against orders. He tells her that Mrs Driscoll is a paranoid schizophrenic who isn’t to be taken seriously. Smells like a cover-up. 

Meanwhile, Hopper remembers that the man who attacked him at the lab was the same man he saw coming out of Mayor Kline’s office. When confronted, Hopper and Kline reach a sort of blackmail stalemate (Hopper pops pills and drinks on the job, Kline does coke and has affairs). Following a good old-fashioned nose-breaking, Kline sings like a canary when Hopper has his finger in a vice, revealing that the man is associated with Starcourt and has been pressing Kline to help him buy property in Southeast Hawkins. 

Hopper has gone full Miami Vice

And not just because of the aforementioned actual vice. His jazzy shirt, bought for the no-show date with Joyce and now co-opted into his uniform, seems to have brought out a rebellious streak in the detective.  

In case you hadn’t already made your mind up, Kline proves he’s an arsehole

He tells Hopper: “Don’t give me that dead daughter sob story, cos I just don’t care.” TWAT.

Stranger Things

The script references Gaten Matarazzo’s real-life physical condition

Gaten Matarazzo has used his platform to spread awareness of cleidocranial dysplasia, a condition he was born with.

In this episode, Steve makes reference to it when they’re working out if Dustin can squeeze through the ventilation shafts at the mall. “He’s got some disease, chrydo-something. Missing bones and stuff – he can bend like Gumbo,” he tells Robin. “Gumby,” she says. “I’m pretty sure it’s Gumbo,” he replies. It’s not, Steve, it’s really not.

There’s trouble in paradise for Nancy and Jonathan

Jonathan hasn’t been supportive of Nancy in her efforts to be taken seriously at work, and this episode sees the two spinning apart from each other. 

We finally get more Erica

The greatest character in Stranger Things history finally comes into her own, recruited by Steve, Robin and Dustin to negotiate the air conditioning shafts at the mall. About time too!

Mrs Wheeler is complicated

So far this season, we’ve seen Nancy’s mum struggle with her attraction to the much younger Billy. In this episode, she does some great mum work, pepping up her daughter and telling her to chase her story no matter what. “I’m proud of you,” she says. “That you stood up for yourself. To those shitheads. If you believe in this story, finish it. And sell it to the Indianapolis Star or whatvever.” Good on you, Mrs W.

Stranger Things

Erica explains capitalism better than most economics lecturers

“You know what I love most about this country is?” she asks Steve and co, who want her to crawl through an air duct for them. “Capitalism. Do you know what capitalism is? It means this is a free market system, which means that people get paid for the services depending on how valuable their contributions are. It seems to me my ability to fit into that little bit is very valuable… I’m talking free ice cream. For life.”

We learn what it feels like when the Mind Flayer gets inside you

“You know when you drop on a rollercoaster?” explains Will. “It’s like everything inside your body is sinking all at once – but this is worse. Your body goes cold and you can’t breathe. I’ve felt it before whenever he was close.” It also, apparently, makes you dead sweaty. 

Will also reveals this nugget of information about the Mind Flayer: “The Mind Flayer likes to hide – he only used me when he needed me.”

Later, Billy describes the entity as “like a shadow, like a giant shadow.”

There’s a callback to Stranger Things 1

El gets a nosebleed in her big battle with Billy, which ends with her propelling him through a wall at the pool. Makes you nostalgic for the buzz-cut days. 

The big questions

Will the gang ever get back together?

Dustin’s been doing his own thing with Steve the whole season so far. 

What’s the connection between those afflicted by the Mind Flayer?

When Billy starts to power up in the sauna, Mrs Driscoll suffers physically too. 

What’s in the boxes in the mall?

Tubes of green goo that look a bit DNA-y. Could be slime, as per the 2018 toy trend. More likely something sinister.

Is the Mind Flayer in multiple hosts?

In Stranger Things 2, when the Mind Flayer was ripped from Will and sealed into the Upside Down by El, that – it seemed – was that. Simple. This time, the big reveal at the end of the episode suggests that the Mind Flayer has spread itself across multiple hosts, making it a hydra-like enemy that is, theoretically, much more difficult to defeat. As the episode pans out, we see dozens of zombie-like Flay-folk. Before it, Heather and Billy spoke. “It was her, she knows now… about me,” says Billy. “Yes. Not us. Not us,” says Heather.

Where is the mall goods depot headed?

Steve, Erica, Robin and Dustin are descending in what was a goods-in depot. But to where? 

The best bits

Best line: Erica to Dustin

“You can’t spell America with Erica”. She’s right, too. 

Other best line: Dustin to Steve

“Touch my ass, I don’t care.”

Other other best line: Erica to Robin

“Whats in this for Erica?” You can’t argue with a child who refers to herself in the third person.

Other other other best line: Mike on Hopper

“He’s just some angry old man who hates joy.”

Best film reference – ventilations shafts are the ultimate skeleton key

An immutable truth of all ‘80s films was that all things are accessible by ventilation shafts. Think: Die Hard. So Operation Child Endangerment, as Erica has it, is part of a grand tradition. “See you on the other side, nerds,” she says, as she disappears. It also feels like a nod to Star Wars: blueprints obtained, weak spot identified, mission set. Starcourt Mall/Death Star… Anyone?

The best am-I-reading-too-much-into-this? film reference

Goonies. Erica’s hard-hat-with-torches feels very like something Data from The Goonies would sport. Especially cos she comments “booby traps” when the goods depot they’re in starts descending.

The other best am-I-reading-too-much-into-this? film reference

Lucas firing a shot from a catapult at Billy. Stephen King’s It, right?

The other other best am-I-reading-too-much-into-this? film reference

When Billy smashes through the sauna door (once it’s got to a Mind Flayer-displeasing 220 degrees). The Shining, right? Heeeeeeere’s BILLY!

The best songs on the Chapter 4 soundtrack

‘We’ll Meet Again’ by Vera Lynne

And that’s it – just this super creepy wartime song playing out over the haunting shit-there-are-loads-of-them scene at the end. 

Read our recap of Stranger Things 3, Chapter 5: ‘The Flayed’