Trust No One
Ezra is a young street rat from the planet Lothal. One day, he steals crates from a crew trying to take them from the Empire. He ends up on the crew's ship, the Ghost.
They are trying to rescue wookies, but the mission goes wrong. The captain, Hera sends Ezra to warn Kanan, Zeb, Sabine, and Chopper. They all successfully make it out, except for Ezra.
Zeb leaves him behind and the crew never comes back for him. Ezra manages to escape on his own, but his trust in people no longer exists.
Some time later, Ezra meets up with the crew yet again.
(So this story is from Spark of Rebellion, but the crew doesn't go back for Ezra.)