A Resistance of Witches

In November 1940, 16-year-old Lydia Polk, a witch and apprentice at the Royal Academy of Witches, a secret London institution that has educated witches for centuries, accompanies her mentor, Isadora Goode, the academy's grand mistress, to 10 Downing Street. Isadora offers Prime Minister Winston Churchill the academy's help against Nazi Germany, breaking a longstanding tradition of secrecy. She acts without approval from the high council, a governing body of 12 elder witches, because the academy's Seers have foreseen that Hitler will overrun Europe unless the witches intervene. Isadora tells Lydia she was chosen for her stubbornness, honesty, and willingness to endure great personal cost, qualities that will "be required."

Three years later, Lydia serves as Isadora's right hand in Project Diana, a secret initiative in which she uses her abilities as a Projectionist, a witch who can send her consciousness out of her body, to track magical objects before the Nazis seize them. Their most dangerous target is the Grimorium Bellum, or "Book of War," an ancient grimoire containing spells for plague, famine, and destruction on a civilizational scale. Nazi intelligence has been forming a coven of young women from magical families, and Isadora believes they plan to use the book at the winter solstice.

During a tracking ritual, the woman who appears to be Lydia's best friend, Kitty Fraser, a shape-shifting Glamourer witch, reveals herself as a blond Nazi assassin who slashes Isadora's throat, steals a fragment of the Grimorium Bellum, and vanishes. Isadora dies in Lydia's arms. Lydia discovers the real Kitty stabbed to death in their shared rooms.

The council moves to select a new grand mistress. Sybil Winter, a retired teacher and motherly figure to Lydia, nominates her as successor, but the council is divided. Mistress Vivian, the eldest Seer, offers support only if Lydia withdraws the academy from the war. Lydia refuses. She finds a breach in the academy's protective warding inscribed with the assassin's rune, proving someone inside allowed the killer entry. When Sybil reveals the council has stripped the grand mistress of wartime powers, Lydia realizes the position is useless and flees to France alone.

In occupied France, Lydia is paired with Rebecca Gagne, a 22-year-old Jewish Resistance fighter operating under a false identity. After Lydia reveals her magic during a militia encounter, Rebecca drives her to Château de Laurier, where Lydia meets Henry Boudreaux, a Black American art curator guarding evacuated Louvre masterpieces. Henry's missing mentor, René Dreyfus, hid the book, but Henry destroyed the magical traces with a cleansing ritual. He agrees to help after Lydia promises to find René.

Under the full moon, Lydia performs a tracking spell through Henry's mind. Her projection locates an abandoned farmhouse and encounters Ursula Wolfe, the Nazi witch who killed Isadora and Kitty, confirming the enemy has its own coven. Henry identifies the farmhouse as belonging to René's Jewish relatives, who were deported. Meanwhile, Rebecca is captured by the Gestapo and tortured by Margot, a rare Nazi Force witch who can control another person's body with spoken commands. Lydia projects to Rebecca and coaches her through carving a hex-breaking sigil that disrupts Margot's control. Rebecca kills Margot and escapes, only to learn her entire Resistance cell has been massacred.

The three travel to the farmhouse, where they find that René died by suicide after the Grimorium Bellum drove him to madness with its whispering. Lydia retrieves the book and discovers she can read its ancient script, but its seductive power begins consuming her. When Rebecca tries to burn it, the book seizes control of her body. After six failed attempts to destroy it, Lydia concludes the academy is the only place capable of securing it.

The Gestapo track them to the château. Lydia casts a plague spell from the book that kills three soldiers but devastates her body. Fiona McGann, a Traveler witch who can teleport, arrives and transports Lydia to London but inadvertently leaves the book behind. Rebecca holds off the remaining soldiers while Henry escapes with the Grimorium Bellum. Carrying it through the countryside, he confronts abilities he has long suppressed: the power to see the dead, inherited from his mother, Fabienne, a Vodou practitioner in New Orleans. A spirit resembling Papa Legba, the Vodou spirit of the crossroads, guides him toward safety.

After harrowing escapes, Henry and Rebecca reunite. In London, Lydia recovers at the flat of her mother, Evelyn, an herbalist who never attended the academy. Evelyn determines that Lydia's magic has been deliberately bound by another witch and reveals that she herself is a Force, a power she has hidden her entire life. Using this ability along with a homemade truth powder, she interrogates a captured Nazi surveillance witch named Gerda Horn. Gerda reveals that the Nazi coven, formally called the Witches of the Third Reich, numbers 11, and that their grand mistress is Sybil Winter.

The revelation recontextualizes everything: Sybil orchestrated Isadora's assassination, manipulated Lydia's nomination, and poisoned her to bind her powers. Evelyn purges the poison and restores Lydia's magic. Lydia plans to destroy the Grimorium Bellum by turning its most devastating spell, The Unmaking, against the book itself. The spell must be cast during the final daylight of the winter solstice and requires a "sisterhood," which Evelyn interprets not as a formal coven but as family.

Lydia recruits Fiona, locates Henry and Rebecca in France, and retrieves the book, but the Witches of the Third Reich attack before Fiona can bring Evelyn. Sybil reveals herself as their leader, captures everyone, and transports them to a castle in Bavaria, arguing that an alliance with Hitler will restore witches to power. Lydia feigns conversion, secretly slipping a protective potion into Sybil's wine. Ursula also unknowingly drinks the dosed wine. Henry and Rebecca escape their cell with help from the spirit of Rebecca's dead mother, Miriam, whom Henry summons.

On the solstice evening, Lydia undergoes initiation into the coven, then leads them in The Unmaking ritual. At the climactic moment, she names the Witches of the Third Reich as the target. A shadow entity within the book consumes each witch, reducing them to ash. Sybil and Ursula alone survive, both shielded by the potion. In the violent aftermath, Sybil breaks free and fatally stabs Evelyn. Lydia kills Ursula with the ceremonial dagger. The Grimorium Bellum bargains to save Evelyn in exchange for its survival, but Evelyn uses her Force power to forbid Lydia from accepting. Evelyn dies in Lydia's arms. Remembering Evelyn's counsel, Lydia spares Sybil to face the high council.

The book, gorged on blood, seizes control of Lydia, convincing her she can end all war by unmaking humanity. Henry and Rebecca return, wrench the book free, and restrain her. Too weak to destroy it alone before the solstice light fades, Lydia receives help when Henry opens the doors in his mind and summons her dead ancestors: generations of Polk women, alongside Kitty, Isadora, and Evelyn. Their spirits join Lydia's chanting, and the book crumbles to ash. In a final moment channeled through Henry, Evelyn's spirit shares memories of Lydia's childhood, says goodbye with a lullaby, and fades.

In the epilogue, set on Victory in Europe Day, May 8, 1945, Lydia emerges from 10 Downing Street as the new grand mistress. Fiona is deployed to hunt escaped Nazi officers; Rebecca is alive in Morocco, pursuing the same work. Lydia prepares to travel to New Orleans, where Henry has returned, the nature of their reunion warmly implied. She and Fiona walk through celebrating crowds, two extraordinary women carrying the weight of all they have lost, allowing themselves both joy and grief as the world begins again.