For the 1969 series of the same name, see The Witching Hour Vol 1.
The Witching Hour was a 2018 crossover written by James Tynion IV. Collected in their respective ongoing series as well as two special one-shots as book-ends, the story chronicles the fight between Wonder Woman and the Justice League Dark against Hecate.
When Diana was twelve, she was marked by the witch-goddess Hecate while spying on a ritual performed by Hecate's amazon witches in Themyscira. When Hippolyta tried to find out what happened to her daughter, Hecate herself appeared, showing her power and making Hippolyta stop any type of research. She told the queen that one day, all of her witch-marked would wake and, with their power, they will give Hecate the whole world to control.
In the present, Diana and Zatanna are debriefing the Justice League about what they have discovered, also telling them of their fight with the Upside-Down Man, a nearly unstoppable force. But when the League, especially Superman and Batman, ask Diana how the creature was defeated, the amazon starts to struggle, as she does not want to tell the truth about her newfound powers that activated back in Salem. Zatanna cuts the question short and they both get back to the Justice League Dark headquarters. Without Diana or Zatanna knowing though, Hecate intervenes making all of the League forget the whole encounter.
As the team gathers to decide the next move to make, Hecate takes control of Diana and Zatanna tries to help her control her power and resist Hecate's strength. Meanwhile, Bobo tries to find help, but with the League unresponsive, because of Hecate's magic, the detective finds an alternative solution: using his Nightmaster sword, Bobo cuts a hole through space letting the team step into the Oblivion Bar, where they will be safe. He does not imagine that just some hour before, Witchfire, controlled by the witch-mark of Hecate, killed several young witches gathered there in a meeting of the Sistehood of the Sleight Hand. In the midst of the carnage, the team finds John Constantine who instantly stands up and kisses Zatanna: he tells her it could be his last chance to do it, as the Witching Hour comes and their lives will probably all be soon lost. 
To understand how to control Diana's new power and how to contrast Hecate, the team, now also with Constantine, goes to the island of Aeaea, the home of Circe, a witch who served as protected of Hecate for a long time. After finding out that Diana was marked, Circe offers help, seemingly moved by compassion. She agrees with Wonder Woman about trying to use Hecate's own power against her, even if Zatanna does not like the idea, thinking Diana should need more time and knowledge. But when Deadman reaches them telling a possessed Manitou Dawn is wrecking Nanda Parbat, Diana and the team decide to leave and try fighting the witch-goddess. Hecate wants to bring the city down as it is one of the places of power of magic: if she succeeds in supplanting it with her own version of the gate to the underworld, Hecate will be one step closer to controlling and reshaping magic in her image. Swamp Thing soon discovers the same thing is happening with the Parliament of Trees, attacked by a possessed Black Orchid, and so he has to abandon the team for duty. Meanwhile, Diana has to surrender to the power of Hecate and only Zatanna and Constantine are there to stop her. Constantine then reveals to Zatanna that after the Upside-Down Man deprived him of his demon blood he developed a lethal form of lung cancer.
Zatanna and John then decide to try a bold move: an exorcism on Diana to get Hecate out of her body. The rite functions, but not in the way the two magicians expected: they are unable to cure Diana, but they cure Manitou Dawn and Black Orchid from Hecate's control with their power converging all in Diana's body. Almost invincible, Diana converts Nanda Parbat in Hecate's Necropolis while it seems the Parliament of Trees is lost, supplanted by Hecate's Parliament of Flowers. Last step is accessing the Sphere of the Gods and destroy Olympus, and then Hecate will control the whole of magic. Meanwhile, the spirit of Diana is in the Collective Unconscious, the home dimension of Hecate. There, the battling will of the amazon prevails and in some way the princess finds a strange passageway under the waters of Hecate's silver lake: she is shocked when she discovers that welcoming her and reaching for her help are the other two aspects of the witch-goddess herself.
The two other parts of Hecate start telling Diana her story: born out of magic before Earth even existed, Hecate soon found out about a dark counterpart of hers, the Upside-Down Man. Scared of him, she created a barrier between herself and the monster, never to feel his presence again. Then, Hecate descended to Earth and for mere curiosity gave the planet a spark of her power. This started an evolutionary mechanism resulting in the creation of the Pantheons of the Gods and the Sphere itself. Innocent and curious, this Hecate was her first aspect, the maiden. Soon, the Pantheons developed and human started to adore them. She wanted to feel part of the life of her creature, becoming the second aspect, the mother. She then chose the Greek Pantheon to be her home, accepting to be venerated in the same way the other Olympians were, and she also accepted to marry one of the Olympians in Hades, the god of the Underworld. Soon though, mortals wanted to rebel against godkind, as they wanted to be the molders of their own destiny: they imprisoned Hecate in a power circle, trying to steal her magic from her.
Screaming for help, she soon found out Hades and the Olympians abandoned her, resulting in her developing feelings of anger and vengeance: the third aspect took control, the one of the Crone. To punish mortals, Hecate reached for the Dark Multiverse and took power from the Upside-Down Man, giving it to humans telling them it was her magic and not a corrupt, cursed power that will haunt them for life. Then, she freed herself thanks to this power and went to Olympus, threatening any god fool enough to challenge her. Then, she waited for her chance to take control of magic, storing her power safely inside the body of five women who remembered her of happier times and showed traits of her previous incarnations.
The maiden and the mother hate the crone, and they want her to be defeated, but to do it Diana must to the unthinkable: getting a brief window of control back, Diana opens the door to the Upside-Down Man, who descends and consumes Hecate herself. With the Sphere of the Gods safe, magic is still unstable but at least not under the control of the crone. While Diana, now without her magical powers, starts to organize a counter-attack against the Otherkind together with Zatanna and the Justice League Dark, Circe laughs in her island as now all the power of Hecate flows in her veins: she was the final witch-marked and, with all others dead, the power of the goddess of witchcraft is all hers and a new goddess is born. The Witching Hour will soon be back, stronger than ever.
- Wonder Woman and Justice League Dark: The Witching Hour #1
- Wonder Woman (Volume 5) #56
- Justice League Dark (Volume 2) #4
- Wonder Woman (Volume 5) #57
- Justice League Dark and Wonder Woman: The Witching Hour #1
Links and References