Anakin and Obi-Wan lead an assault on Umbara. Equipped with their own, unique weapons, the clones struggle in the darkness of Umbara against the Umbarans. Anakin is relieved of his duty from the 501st by Chancellor Palpatine and replaced with Jedi Pong Krell. Krell leads Rex and the 501st into danger time and time again, starting distrust between the clones. Fives, Jesse, and Hardcase make the reckless decision to go destroy an enemy supply ship on their own, which will be the tipping point for Krell.