Star Wars: The Clone Wars - Season 4 Episode 10 -

"Carnage of Krell" With two of his men (Fives and Jesse) facing execution for disobeying orders, Captain Rex is forced to confront his overly aggressive commander, General Krell, in the conclusion to the action-packed battle for Umbara. Risking charges of mutiny, Rex must make a dark choice as the true face of the enemy emerges.