Luke Skywalker (Mark Hamill) has gone into hiding, and the Galactic Empire 2.0—aka the First Order—has been up in everyone's face.
A brave resistance movement is fighting the First Order, aided by the Galactic Republic and General Leia (Carrie Fisher), who knows her brave resistance movements.
They're all looking for Luke because he's the last of the Jedi and could come in handy, but no one knows where he's gone.