Part 04 - Tower Infiltration

Looks like 9S went and broke himself so it's not avisable to go anywhere but the Resistance Camp until he's fixed. Then you can go get the final key from the Resource Unit at the Amusement Park. This one is not that much different from the Meat Box in the sense that you need to defeat all the enemies on a floor to progress to the next. In any case, the game switches to A2 briefly after 9S enters the elevator. Have A2 go after him and control should switch right back to crazy boy.

Start climbing to the top of the structure where your former Operator is waiting. Here you need to destroy the two rows of defense systems in front of her first. They fire both orb projectiles and lasers. It's not easy to move in close at all here, so you might want to rely on your pod to do damage while you focus on dodging. Or just hack it to destroy it quick. Attack Operator 21O after taking care of her defenses, and the actual fight starts when she gets back up. What's interesting (and really sad) is the dialogue you get if you allow 21O to live long enough. I had hoped there was actually a way to avoid killing her.

Defeat her and another boss should drop in. This one is called Auguste and A2 will be the one fighting it. Kill it and control should switch back to 9S once again. You should have all the access keys in your possession now, so head back to that tower in the middle of the City Ruins. Deactivate the the locks on the three smaller sub-units so you can hack into each of them.

Once the lock on the main tower is deactivated, you can start trying to hack it, but while enemies start to arrive in droves. Papola and Davola arrive to keep the enemies busy so you can hack into the tower undisturbed. Only destroy the enemies that get too close and keep hacking until you get into the tower's system. 9S is unable to complete the task however, and the twins resort to doing something drastic to get him in.

There are two possible endings for you to unlock here. The first is Ending S where you abandon the twins by leaving the combat area, and the other is Ending V which requires you to ignore the tower and fight alongside the twins until they run out of energy.