The stars behind new and familiar “Stranger Things” characters preview the “absolutely insane” production.

Its part of the job when you joinStranger Things.

You know, spoilers!

Stranger Things: The First Shadow

Louis McCartney as Henry Creel in ‘Stranger Things: The First Shadow’.Manuel Harlan

“It would ruin the beginning of the show, adds Isabella Pappas, playing young Joyce Maldonado.

(Adult Joyce, as fans know, is portrayed byWinona Ryderon the TV series).

The answer is so vague not even her costar, Louis McCartney, a.k.a.

Stranger Things: The First Shadow

Louis McCartney as Henry Creel in ‘Stranger Things: The First Shadow’.Manuel Harlan

young Henry Creel/future Vecna, knows what shes talking about.

McCartney exclaims, jogging his memory.

Thats one of my favorite scenes.

Stranger Things: The First Shadow

Louis McCartney as Henry Creel and Patrick Vaill as Dr. Brenner in ‘Stranger Things: The First Shadow’.Manuel Harlan

McCartney hypes it up best: “It’s absolutely insane.

[It will] blow your mind away.”

Fans of the TV drama know the name Henry Creel, a.k.a.

Stranger Things: The First Shadow

Louis McCartney (Henry Creel) and Patrick Vaill (Dr Brenner) share the stage in ‘Stranger Things: The First Shadow’.Manuel Harlan

“Henry Creel is on a journey with his family,” McCartney explains.

Lurking in the periphery of Henry is Dr. Brenner.

“She’s a bit of a nerd, but in the best way,” Williams adds.

Stranger Things: The First Shadow

Louis McCartney as Henry Creel in ‘Stranger Things: The First Shadow’.Manuel Harlan

“She’s really into comic books, and she comes across very confident and sassy.

Meeting Henry helps her come to terms with who she is.

I feel like they both figure each other and themselves out through getting to know each other.”

Stranger Things: The First Shadow

Louis McCartney’s Henry Creel shows his talents to Ella Karuna Williams' Patty Newby in ‘Stranger Things: The First Shadow’.Manuel Harlan

“The kids grow up and thentheirkids are the same as what they were.”

Pappas sees Joyce as more of an outcast in high school.

She’s currently working on a play, which creates this play-within-a-play forThe First Shadow.

Stranger Things: The First Shadow

Isabella Pappas as Joyce Maldonado, Christopher Buckley as Bob Newby, and Oscar Lloyd as James Hopper Jr. in ‘Stranger Things: The First Shadow’.Manuel Harlan

“Especially being a teenage girl in the ’50s is interesting.

She sticks out a lot more in that time period than she does maybe in the TV show.”

But that doesn’t stop her flirtation with Hopper.

Stranger Things: The First Shadow

Joyce (Isabella Pappas) leads a room with Claudia Yount (Maisie Norma Seaton) and Sue Anderson (Kemi Awoderu) in ‘Stranger Things: The First Shadow’.Manuel Harlan

Hopper, meanwhile, is 18 when we find him at the start ofThe First Shadow.

“His dad never got out of town, and for Jim, it’s a big thing.”

“He is very much a loser in the school and in social circles.

Stranger Things: The First Shadow

Hopper (Oscar Lloyd) grapples with his dad, Chief Hopper (Shane Attwooll), in ‘Stranger Things: The First Shadow’.Manuel Harlan

The trio form an unlikely bond once strange things start to happen in Hawkins.

“They’re just slightly less traumatized maybe,” Pappas responds.

“But they’ll get there!

Don’t worry.”

Guess that’s not too much of a spoiler.