This is the level after you and your companions have been arrested by the Marquis and you have been sent as prisoner of Judge Ghis, who is the Commander of the Leviathan and the Western Armada, whilst being sent to the cells, Vossler attacks the Imperials and rescues you in the disguise of and Imperial Judge who is looking for Ashe.
As soon as you start at the Port Launch area, there is a save crystal to the left of the doorway, after you have saved (or not as the case may be...) you must go through the double doors which afterwards Vossler explains about the Laser mechanism, you must fight loads of Imperials on the way especially Imperial Hoplites and Imperial Magus.
After you have found your way to the Heavy Freight area, there are 3 treasure cases, these have gil and a Hi-potion in them so it is better to collect them as when you return the caskets will respawn (not if you re-enter the room straight away...).
In the Circular corridor the passageway to the centre cells are both blocked by a laser defence system which you have no choice in setting off so the best thing to do is to use the fleeing tactic as you need your health for the next battle.
Imperial Assault 2 Judges, 2 Magus, 4 Imperial Swordsmen
This is a really simple battle if your Gambits and characters are well equiped, the best thing to do is to Take out the Magus first as they use a lot of negative effect spells like Poison and Blind, then take out the swordsmen and finally take out the Judges.