Grand Admiral Thrawn discovers the location of Chopper Base and ambushes the Rebels in the season 3 finale.
Ezra purposely gets captured by Imperials over Lothal as Thrawn closes in on Fulcrum's identity.
Captain Rex faces his past when the Rebels encounter a cell of Separatist battle droids still fighting the Clone Wars.
Grand Admiral Thrawn returns and makes things quite difficult for Hera and company during their foray on Ryloth.
Sabine Wren goes undercover to help some Imperial cadets defect from their academy.
Rebels makes it's return with an action packed hour long premiere episode.