In 22 BBY, on the planet Rattatak, at a combat ring called the Cauldron, Dooku went to the Cauldron in an attempt to find an assassin for the CIS. There he encountered a mysterious fighter who dominated every opponent in the combat ring with the skilled use of the Force and her lightsabers. She introduced herself to him as Asajj Ventress, a Sith warrior. After denouncing her claims to be a Sith, Dooku challenged Asajj in combat and defeated her. Dooku denied that she was a Sith, pointing out she had fear, a feature Sith do not have. Ventress tried to kill Dooku, enraged at this comment, but Dooku used Force lightning to knock her unconscious.
Ventress awoke after a long sleep. She found her lightsabers on a table. Dooku came at her surprisingly, forcing Ventress into a duel. Ventress Force jumped and grabbed her lightsabers. The duel began. They both dueled with all their anger at each other. Dooku taunted Ventress by saying that if she was a Sith, she would have defeated him quickly. This enraged Ventress, and caused her to become reckless in her attack. Dooku finally pulled her lightsabers and chopped them in half, winning the duel.
Dooku was so impressed with her skills that he presented her to Darth Sidious, who was watching via hologram, and gave Ventress an important assignment—assassinate Anakin Skywalker. Ventress, after receiving Komari Vosa's lightsabers, left in a Fanblade starfighter to kill him.
- Star Wars: Clone Wars – "Chapter 6" (First appearance)
- Star Wars: Clone Wars – "Chapter 7"
- Star Wars: Clone Wars PhotoComic