Diana Bishop (Palmer) is an American professor of history from Yale visiting a college at Oxford in the UK. There Diana soon stumbles upon a bewitched book in the Bodleian Library. Herself a witch by birth, Diana has refused to do magic for years, but is forced to face it again because of the secrets this book holds. She receives help from the mysterious vampire and geneticist Matthew Clairmont, in spite of the mutual antagonism between their people. While working together, they strike to uncover the book's secrets and protect it from the threats in the world of magic.
The series has been announced as being renewed for a second and third season.
- Adaptational Diversity: In the TV show, Em is a black woman, descended from Tituba. Agatha and Nathaniel Wilson are also black.
- Dark and Troubled Past: Diana's parents were killed by muggles who'd found out they were witches. Since then, she's refused to use magic. Until we find out that it was actually witches who killed them and covered it up.
- Daywalking Vampire: All vampires in this universe appear to be completely unaffected by sunlight.
- Does Not Like Magic: Diana's refused to use magic ever since muggles killed her parents over having it.
- Friendly Neighborhood Vampire: Matthew. He appears to refrain from drinking human blood at all, and is never anything less than a kind man who's a proper English gentleman.
- Great Big Book of Everything: The Ashmole Manuscript, also called the Book of Life. It contains all magical secrets of everything.
- Has Two Mommies: Diana was raised by her lesbian aunts after losing both of her parents as a child. They appear to have served as surrogate parents ever since.
- Identical Grandson: Aisling Loftus plays Sophie Norman Wilson and her ancestor Susanna Norman
- Interspecies Romance: Diana starts one with Matthew. It turns out this violates the Covenant, a treaty between witches, demons and vampires which forbids such relationships due to fears it would upset the balance of power between them.
- Lipstick Lesbian: Diana's lesbian aunts are indistinguishable from other middle-aged women aside from their sexual orientation.
- Living MacGuffin: The Book in some ways. At least, it seems to make decisions about who gets to find it and who doesn't.
- The Magic Goes Away: Magic is fading from the world, with witches' spells no longer nearly as powerful, demons going mad increasingly and vampires unable to create more of their kind. Matthew states that if this happens, the humans will eventually notice it and find the world entirely dull.
- The Magic Comes Back: Or, that's the plan anyway. With The Book in the right (or wrong) hands the magic that's all but vanished could be brought back.
- Masquerade: Witches, demons and vampires all keep themselves hidden from normal humans. Diana is always keen to assure others no muggles saw when she accidentally did magic.
- Our Vampires Are Different: They look indistinguishable from humans ordinarily, are unaffected by sunlight, don't age, have superhuman strength and speed and turn others by giving them some of their blood.
- Really 700 Years Old: Matthew estimates he was born about AD 500, and became a vampire in around 537, making him over 1500.
- Rule of Three:
- The Congregation is a governing council consisting of three members of each of the three species (vampire, witch, and demon).
- In season one, Diana spontaneously manifests control over the elements on three different occasions: first, she summons wind, then rain, and finally fire.
- Shout-Out: The title is related to The Discovery of Witches by real witch hunter Matthew Hopkins, explaining witches supposed characteristics along with how they could be hunted down.
- Vampire Bites Suck: There is nothing romantic about being bitten by a vampire here. It's shown as causing realistic pain, and leaves a victim greatly weakened assuming they survive at all.
- Vegetarian Vampire: Matthew only appears to feed on animals, along with the rest of his family. An exception is when he attacks Gillian.
- Voluntary Vampire Victim:
- Jack and other vampires have humans who allow the vampire to feed on them in exchange for money and other favors.
- Diana lets herself be bitten to save Matthew's life after Juliette attacks him.
- Witch Species: Witches are another species distinct from humans in the series. People must have one witch parent at least to do magic. However, they still look the same.