A Viper probe has landed on the ice planet Hoth near the Echo Base. Darth Vader and his Imperial fleet, armed with Storm Troopers and a lumbering battalion of AT-ATs, have been alerted to Rebel's presence. Damaged shield generators have come online, although struggling to maintain power they should be able to withstand the airborne offensive, but the ground assault is bearing down. Massive numbers of the Empire's 501st Legion troops combined with AT-AT and AT-ST's are congregating near the outskirts of the Echo base, ready to strike the final blow to our Alliance. Outward command posts are vulnerable, and will be the first to fall. Hasty defenses are being constructed around the main power generators as they are likely to be the primary target- but these won’t last long. Rebel forces must fortify the perimeter of the Echo base until a window opens for an escape.