The Imperials have found a Rebel base and set up an Interdictor cannon which prevents the Rebels from escaping.
Play as the RebelImperial Infantry, or RebelImperial Air Force in an attempt to destroy the Interdictor Cannon so you can escape, or crush the Rebel command buildings.
Delicately balanced, must have 4 players for each army to be comparable. Rebel air units are more powerful than Imperial's, but Imperial ground forces are stronger.