Star Wars: The Clone Wars - Season 4 Episode 14 -

"A Friend in Need" A peace conference between Separatists and Republic delegates is interrupted by Lux Bonteri, the son of the late Separatist Senator, Mina Bonteri (Season 3, Episode 10). Soon after, he involves Ahsoka in his dangerous search to find justice for his mother's death - which subsequently leads to Ashoka crossing paths with Vizsla and the Death Watch.