Let’s get the bad news out of the way: A Discovery of Witches season 4 is almost certainly not happening. The show’s UK channel Sky One and U.S. platform AMC Plus announced ahead of time that the third season would be the last. That also aligned with Deborah Harkness’ All Souls trilogy — one book per season.

A Discovery of Witches follows Diana Bishop (Teresa Palmer), a historian and a non-practicing witch, who finds a magical spellbook in Oxford’s Bodleian Library. Her discovery brings a vampire and geneticist, Matthew Clairmont (Matthew Goode), to her doorstep. As they work together to investigate the book, they fall in love. But their alliance unleashes a host of threats from other creatures.

The show has proved to be enormously popular with fans on both sides of the Atlantic. This wouldn’t be the first time that producers declared a show would only have a certain number of seasons and then went beyond that. Nor would it be the first time an adaptation evolved beyond the original books.

So, let’s dig into the A Discovery of Witches season 3 ending, whether a fourth season could work and the possibilities of other shows — say, a Gallowglass spinoff.

A Discovery of Witches season 3 ending, explained

After finding out that Matthew’s son Benjamin (Jacob Ifan) is torturing him, Diana sets off for Poland to rescue him. She battles against the antagonistic witch Satu (Malin Buska), but Diana proves more powerful and binds her.

She uses her magic to create a bow and arrow, with which she kills Benjamin. The injured and weak Matthew is taken back to Sept Tours, where he is healed by Ysabeau (Lindsay Duncan).

From The Book of Life, Diana learns that the key to everything is daemon DNA. Matthew has it, which is why he experiences blood rage. The recession of daemon DNA is also why vampires’ lives have been shortened and witches’ powers on the decline. The Covenant that keeps creatures apart has actually endangered them.

Diana goes before the Congregation to reveal all. She argues that witches, vampires, daemons and humans are related and need to intermarry. Despite opposition from vampire Gerbert (Trevor Eve), the Congregation votes to abolish the Covenant and elects daemon Agatha as their new leader.

Afterward, Diana and Matthew celebrate at Sept Tours, surrounded by family and friends.

A Discovery of Witches season 4: Plot ideas

If — and this is a giant if – A Discovery of Witches season 4 did get made, what could it be about? Diana and Matthew’s journey to find the Book of Life has ended happily ever after.

One idea is that season 4 is adapted from Harkness’ upcoming book, The Serpent’s Mirror. Diana and Matthew return to Sept Tours to settle into a quiet life, but she discovers something shocking in the archives about Queen Elizabeth’s rise to the throne. Matthew acted as a vampiric double agent in the Tudor era, and Diana digs into her husband’s past to find out what really happened in November 1558.

A Discovery of Witches: Gallowglass spinoff

We have to admit, though, a fourth season seems pretty unlikely. A greater possibility is A Discovery of Witches spinoff (or several).

Harkness wrote another a fourth book in the All Souls universe, Time’s Convert, which focuses on Matthew’s vampire son Marcus Whitmore. It’s set in the present day as well as the Revolutionary War. First turned in the 18th century, Marcus falls in love two hundred years later with a human, Phoebe Taylor. She decides to become a vampire herself, but her transformation will be as challenging as his when he was first sired by Matthew.

Harkness is also working on two other All Souls novels, one centering on Gallowglass. Actor Steven Cree, who plays the soulful vampire warrior, has previously stated he would sign on for a spinoff.

“I would 100 per cent be up for more Gallowglass,” he told Digital Spy. “Gallowglass is a great character. It’s been like playing two characters because in season 2, he is like a rock ‘n’ roll vampire in the Elizabethan era, and in season 3, he is a motorbiker vampire.”

He also told Radio Times , “You can tell endless stories about Gallowglass. He’s been alive for eight centuries. And he’s such a great character.”