In LEGO STAR WARS: REBUILD THE GALAXY - PIECES OF THE PAST, Sig Greebling (Gaten Matarazzo) tries to rescue his brother Darth Dev (Tony Revolori) from the dark side while the fate of the galaxy hangs in the balance. Sig is training to be a Force Builder on planet Alistan Nor under the guidance of Jedi Bob (Bobby Moynihan) when he starts dreaming that brother Dev is in trouble on planet Dathomir. Meanwhile, Sig's friend Yesi (Marsai Martin) is frustrated that her rebel talents are wasted on her boring supply run missions. Suddenly, a Mandalorian appears and kidnaps the gang. They learn that Solitus, Jedi Bob's former master, has gone over to the dark side and hatched a plan to destroy the entire galaxy. Sig, Jedi Bob and Yesi must work together with Dev and other unlikely allies to thwart Solitus and restore the galaxy.