Of course, navigator Meyer has a bad feeling about it - not entirely unfounded, as the moment the Karosas fleet and the Argo begin preparations for landing and remotely opening the Castle, another dropship arrives at the scene, heading for the same spot. Kamea makes a judgement call and expedites the mission. Looks like it's never going to be easy.
* The game doesn't do you a solid in this instance, as you are deprived of one of your regular pilots and forced to bring Kamea along, without the ability to alter her loadout. She's a decent Gunner, but with unremarkable other skills (8/3/5/4) and her default loadout is decent, if uninspired. If you invested in traveling the world a bit and salvaged a few mechs, you might already be sporting heavies in the 70 ton range. Pack those to save a headache.
* Once you land, make your way to the marker at the armory. Farah will inform you that the regular approach doesn't work, so she'll try something different. And as it turns out, slightly stupid: The vents around the armory start spitting out SLDF drones like there was no tomorrow while the Argo goes dark. You have a total of six SLDF drones to take care of, appearing in front of the gate and behind you.
* After you wipe them out, it's time to face the second stage of the battle: The Castle will activate its defensive turrets, more drones will pop out, and you have no choice but to force your way in, as the automated systems are bound to knock the Leopard out of the sky with ease.
* After a good ten rounds of fighting off waves of drones, Dr Murad will finally find the authentication codes. The problem with the Argo was caused by malicious code she accidentally released when she used the codebreaker on the memory core of the ship. It did give her encrypted files, while turning every alarm in Castle Nautilus on. Arano will be relieved and order the lance evacuated, taking Yang into the Castle to recover whatever's within it.
* You secure Nautilus, the ARS Delfinas is en route, and you get to salvage some vintage weapons off the drones. Not too shabby, right? Of course, there are the unwelcome guests to take care of...