The Imperials are at the very door of the command centre. Braxus launches off a stream of shots to put their heads down. "Right, we're going," he grabs the arm of your last man, physically dragging him out of the room towards the tunnels. You meet in the lower passages; all shaken, some injured, and quite ready to get out, which you promptly do as you race off down the tunnel.
The Imperials are following behind you, just out of sight as you drop into the sewer entrance. Braxus sends you on, planting a thermal detonator on proximity setting in the entrance you just came through before following on. You race down the tunnel as fast as you can, until a sudden blast and concussive wave of hot air from behind bring you up short. You look back down the passage, but no pursuit follows. Shakily, you follow the other Rebels out until you emerge from a storm drain at the very edge of the city just as dawn breaks over the far mountains.