Star Wars Rebels Season 1 Episode 4 - Breaking Ranks

Ezra goes undercover as an Imperial Academy cadet to help foil a shipment of kyber crystals. During his operation, he befriends fellow cadets Zare Leonis and Jai Kell, the former of whom has similarly infiltrated the academy in search of his missing sister Dhara. After completing the mission, Ezra discovers that the Inquisitor intends to take him and Jai prisoner. With Zare and the other rebels' help, the three are able to fight their way out of the facility during an Imperial walker training exercise. Jai goes into hiding while Zare remains at the academy to continue his search for Dhara. From Wikipedia