Production on Stranger Things season three is currently underway, with the cast set to film the final two episodes soon.

And while the series will not return until summer 2019, fans will get a sneak peek at what is to come in the forthcoming season in the show's official behind-the-scenes companion book, Stranger Things: Worlds Turned Upside Down.

The official guide to the Netflix sci-fi giant gives readers the chance to unravel the mysteries of the series, as well as hidden messages written in Morse code used by lead character Eleven (Millie Bobby Brown).

Secrets unravelled: Stranger Things official guide will let fans decode hidden messages and be given a sneak peek at season three, it was revealed on Friday (pictured Millie Bobby Brown)

The 224-page book was created by Penguin Random House in partnership with Netflix, and features cover art by Kyle Lambert, who designed the 80s-style posters for both seasons, with a worn and torn design.

Inside is a detailed guide on the show from first pitch to early drafts of screenplays, and even gives readers 'a look into the future of the series — including a sneak preview of season three.'

While it's unclear exactly what this sneak peek might include, one exciting feature that is sure to entertain readers is Eleven's Morse code decoder, which will teach them how to read the secrets messages that are hidden throughout the text.

80s style: The 224-page book was created by Penguin Random House in partnership with Netflix, and features cover art by Kyle Lambert with a worn and torn design

Mission: One exciting feature that is sure to entertain readers is Eleven's Morse code decoder, which will teach them how to read the secrets messages that are hidden throughout the text

But that's not all, as the book also has Dungeons and Dragons inspired character bios, particularly for Dustin (Gaten Matarazzo), which shows player character sheets, and is complete with vital stats.

There is also a 'Monster Morphology' spread, which presents the evolution of the Upside Down's ominous villain from Pollywog to Demogorgon including details on what made season two creature Dart distinguishable.

Set to be released in time for Halloween on October 30, the book will also include a foreword from creators Matt and Ross Duffer as well as interviews with the stars, and even a map of the fictional town of Hawkins, Indiana.

Cool: But that's not all, as the book also has Dungeons and Dragons inspired character bios (pictured, Dustin's bio), which shows player character sheets, and is complete with vital stats

More details: There is also a 'Monster Morphology' spread, which presents the evolution of the Upside Down's ominous villain from Pollywog to Demogorgon

As well as the companion book, Penguin Random House have plans in place for a series of books based on the show which will expand the franchise.

According to Deadline, one will be a prequel to the series, written by Gwenda Bond, which will reveal the backstory of Project MKUltra and Eleven's mother Terry's involvement in it, a narrative which was first introduced in season two of the show.

Several books for both adults and young readers will be released in 2019, while an as-yet-untitled gift book will come with the official guide and offer 'advice, wisdom, and warnings from the Stranger Things world' to readers.

While the third season is set exactly one year after the events of season two, fans will have to wait until the summer of 2019 to see what happens next.