The ninth episode of the Star Wars: The Clone Wars television show is entitled "Cloak of Darkness". Positioned as the ninth episode overall, it resides within Season One and continues the narrative arc initiated by the preceding episode, "Bombad Jedi," forming the second act of a three-part story.
The official synopsis reads: Ahsoka and Jedi Master Luminara are tasked with escorting the captured Viceroy Nute Gunray to stand trial. Little do they know, Count Dooku has deployed his lethal apprentice, the assassin Asajj Ventress, with the mission to liberate the prisoner and eliminate the Jedi.
Jedi Master Luminara Unduli takes custody of Viceroy Gunray aboard the starship Tranquility, with the intention of transporting him to Coruscant to answer for his war crimes. Accompanying her are Ahsoka Tano and a contingent of Senate Commandoes under the command of Captain Faro Argyus. Ahsoka questions the need for such heavy security, but Unduli assures her that the Neimoidian is more formidable than he appears, hinting at potential conspiracies by his allies.
Meanwhile, Darth Sidious informs Count Dooku that Gunray's interrogation poses a grave threat to their plans. Dooku assures him that a plan is already in motion: he's dispatching his top assassin, Asajj Ventress, to either rescue Gunray or ensure his silence, despite her past shortcomings. Sidious expresses reservations but ultimately approves the operation. After Sidious departs, Dooku emphasizes to Ventress that failure is unacceptable, to which she vows to prove her ability to defeat the Jedi.
Back on the Tranquility, Unduli and Ahsoka begin their interrogation of the Viceroy. When Gunray proves uncooperative, Ahsoka resorts to threats, earning a reprimand from Unduli. Nevertheless, the threats prove effective, prompting Gunray to begin talking. However, their interrogation is interrupted when a squadron of Vulture Droids, escorting three Separatist boarding ships, launches an attack on the Tranquility. Super battle droids storm the Cruiser, swiftly eliminating the majority of the first wave of clones. As the fighting subsides, Ventress enters the hangar and spots a lone clone struggling to his feet. Noticing her, the clone is immediately attacked by Ventress, who ignites her lightsabers and charges. Deflecting the trooper's blaster fire with ease, Ventress decapitates him before he can send a warning, stealing his communications equipment to monitor the clones' movements. Commander Gree, along with a squad from Green Company, and Unduli depart to confront the droids, leaving Ahsoka to guard Gunray. Ventress infiltrates the engine room and plants thermal charges on the cruiser's generators before heading to the brig. With the Super Battle Droids destroyed, Ventress becomes the sole enemy combatant remaining on board. She briefly duels Ahsoka before trapping her inside Gunray's cell. Unduli's timely intervention prevents Ventress from rescuing Gunray, but the assassin detonates the charges, causing the ship to shake violently before escaping down an elevator shaft. Despite Ahsoka's warnings that Ventress is too dangerous for a single Jedi, Unduli pursues her, confident in her ability to defeat the assassin. Argyus advises Ahsoka to follow her instincts, while Gree insists she obey orders. Gunray's self-serving remark, "All I know is I never risk my own skin if I don't have to", draws glares from Ahsoka, Gree, and Argyus. Ultimately, Ahsoka decides to assist Unduli.
In the generator room, Ventress and Unduli engage in a duel. Unduli is quickly overwhelmed as Ventress, enraged by Unduli's mocking of her fighting style as an inferior imitation of Dooku's, defeats and traps her beneath fallen pipes. Ahsoka arrives just in time to save Unduli, but Ventress escapes once more. Ventress then activates a signal. Back in the brig, Argyus receives the signal and betrays his fellow commandos, freeing Gunray and revealing that he was bribed by Dooku to aid in the viceroy's rescue. Commander Gree manages to subdue him after a short scuffle. Gree demands to know Argyus's motives, to which Argyus replies, "A clone like you wouldn't understand but I wanted a life filled with more than empty servitude." Disgusted, Gree retorts, "And for that you'd betray the Republic." Argyus replies "It's like I told the Padawan: Sometimes being a good soldier means doing what you think is right" and reaches for his blaster. Gree intercepts him and knocks him out. Gree snarls, "You and I disagree on what makes a good soldier" and prepares to kill the turncoat. However, he fails to account for Nute Gunray. The Nemoidian picks up a blaster and struck the clone in the back of the head. The blow instantly knocks Gree unconscious . They escape on the docked Republic ship in the lower hangar, joined by Ventress, who uses an escape pod. Argyus boasts that he will receive the majority of the credit in his report to Count Dooku, but Ventress impales and kills him.
Later, Unduli and Ahsoka report the mission's failure to Yoda and Anakin Skywalker. They learn that the stolen ship might be tracked. Ahsoka departs to join Skywalker with Kit Fisto's fleet, but not before receiving an apology from Unduli for disregarding her concerns about Ventress.
During Dooku's conversation with Sidious, he is wearing his cape. However, when Ventress enters the room immediately afterwards, the cloak is gone.
When Ahsoka arrives, she is seen carrying Luminara's lightsaber, cuts Luminara free with it, and then hands it back to her. All the while, her own lightsaber is not clipped to her belt, nor seen anywhere. However, when Ventress attacks them both, suddenly Ahsoka has her lightsaber.