The nineteenth episode of the Star Wars: The Clone Wars animated television show's fourth season is titled "Massacre". It marks the commencement of a narrative arc spanning four episodes, focusing on the fate of Asajj Ventress, the Nightsisters, along with a pair of Nightbrothers. Its original broadcast date was February 24, 2012.
"Driven by a desire for vengeance following the Nightsisters' act of treachery, Count Dooku resolves to inflict retribution upon them on Dathomir. Under his command, General Grievous initiates a comprehensive droid assault on the magic-wielding witches. In response, Mother Talzin and Asajj Ventress spearhead the defense, harnessing the full extent of their dark powers."
After a period spent in hiding after Savage Opress's betrayal during her attempt to get revenge on Count Dooku, Asajj Ventress makes her way back to the Nightsisters' base of operations on Dathomir, where Mother Talzin warmly welcomes her return. Talzin suggests that Ventress relinquish her aspirations of becoming a Sith and instead fully immerse herself back into the Nightsisters' ranks. Ventress concurs and participates in the initiation ceremony, thereby solidifying her position as a fully accepted member of the coven once more.
However, Dooku has neither forgotten nor forgiven the attempt on his life, and he instructs General Grievous to proceed to Dathomir with the objective of exterminating the Nightsisters. The droid armies launch a full-scale assault on the initiation celebration, prompting the Nightsisters to brace themselves for combat. The Nightsisters, led by Ventress, begin to launch a counteroffensive, but as soon as Ventress is visible on the battlefield, Grievous deploys a squadron of defoliator tanks with the intention of swiftly eliminating their adversaries. Ventress succeeds in destroying the defoliators and advances directly towards Grievous, challenging him to a one-on-one duel, which Grievous promptly accepts.
Simultaneously, Mother Talzin enlists the aid of Old Daka, the order's revered elder, to resurrect deceased Nightsisters using dark magic, thereby creating an undead army to resist the Separatists. Old Daka unleashes her power, causing the remains of the dead to emerge from their burial chambers and join forces with their living counterparts. Talzin employs a strand of Dooku's hair, previously acquired and secretly stored, to fashion a magical voodoo doll resembling Dooku. Through this effigy, she channels her magic to inflict torment upon him, demanding that he cease his attack or face a painful demise.
During a lightsaber confrontation, Ventress gains the upper hand against Grievous, but the cunning cyborg orders his droids to resume their assault. Grievous is on the verge of killing her, but the undead army intervenes, attacking Grievous. Wounded and witnessing the deaths of her sisters, Ventress is compelled to flee. Summoned by Dooku, Grievous locates the source of Talzin and Daka's magic. He begins by eliminating Daka, thereby disrupting the resurrection spell. Without reinforcements, the remaining Nightsisters are brutally massacred. Before Grievous can execute her, Talzin transforms into smoke and disappears. The apparition of Talzin subsequently appears before Ventress, assuring her that while her destiny will forever be intertwined with the Nightsisters, Ventress now has a new path ahead. Talzin vanishes, leaving the forlorn Ventress to confront an uncertain future.
The Director's Cut of this episode was featured on the Star Wars: The Clone Wars The Complete Season Four DVD and Blu-ray releases.