For this level you’re basically going to be escorting the Little Sister to the end, so she can open the last door for you to take you to Fontaine. Her health bar is just underneath yours. The little sister is fairly fragile, so try to kill splicers and other enemies before they get too close to her. Your little sister’s location is noted by the “goal” marker on your map, in case you lose track of her. Another thing to note is that security cameras will not sound the alarm when they see you (since you look like a big daddy). You may still want to hack them to get their help fighting splicers.
Follow the little sister up the stairs, around the corner past the Vita-Chamber, and into the main museum area. You’ll head left down the balcony and through a door. Keep following the little sister (I’m going to be saying that a lot in this level, sorry) and kill any splicers you bump into as you round the corner. You’ll eventually come to a bend by a window with a security camera above it. On the ground is a corpse – this is apparently the area they used to train little sisters. Your little sister will stop for a while to try to gather ADAM from the corpse. Hack the camera so it’ll help you against the splicers who are about to attack you.
The little sister will eventually finish stabbing the corpse and start walking down the hall again. Right around the corner is another “test subject” with a security camera – same drill here. There’s also a turret keeping watch at the end of the hall, hack it too. Kill off the splicers and wait for the little sister to finish up. Head around the corner with the little sister and kill the turret. The little sister will open the door – head on through.
You’ll head back out into the main open area of the museum. In an alcove to your right as you walk down the wall is a turret – zap it and hack it or just kill it. There’s also another turret on the other side of the room, directly across from the first one and behind the skeleton, so watch out. As you enter the next hallway, some splicers will jump up out of the water. Kill them, and continue on. You’ll eventually come to another “test subject”, with a turret and camera through the alcove to your left. Let the little sister do her thing, then continue on down the hall. As you come around the corner you’ll have to fight one last big daddy. Take him out, and follow the little sister through the door and across the balcony.
You’ll come to a room with a ton of loot and machines in it. This is your last chance – get everything that you need. Make sure that you slot in your elemental protection gene tonics (Human Inferno, Frozen Field, Electric Flesh) as you’ll need them for the last boss. Other than that, just make sure you are well stocked up on ammo and especially first aid kits/EVE hypos.
If you look at your map you’ll see two little rooms just off the balcony you came into this room from. Each one has some loot and ammo for you.
When you’re ready, grab the hypodermic needle from the little sister and head up the elevator. Time to take down Fontaine once and for all.
ENDGAME
The game should save automatically as you get out of the elevator at the top. You can’t save in this area, and there is also no Vita-Chamber. If you die, the game will automatically quit to the main menu, and you’ll have to start over. You’ll see Fontaine ahead of you, strapped into… something.
You need to drain the ADAM from Fontaine using the needle the Little Sister gave you. The only time you can do this is when Fontaine is vulnerable, sitting in the machine at the center of the room. Once you drain him the first time, he’ll jump out and attack you. To get him to go back to the machine, you have to reduce his health nearly to zero, and he’ll run back to repair, letting you drain him again. You’ll have to do this three more times in order to defeat Fontaine.
There are three stages to the fight. In each stage Fontaine has a different elemental power – first fire, then ice, then electricity. The key is to attack him with elemental damage damage that’s opposite to what he’s using in this phase – ice or electricity in the first phase, fire or electricity in the second, and fire or ice in the third. Your chemical launcher and plasmids, as well as all your other elemental ammo, is your best friend here. Explosives are also extremely effective on him, especially in the final phase.
The key to this fight is speed. There will be splicers and security bots spawning in the second and third phases – ignore them for as long as Fontaine is not in the machine. When he goes back to repair, you can use the bot shutdown panel on the north wall (and the medical station behind it), but ignore the splicers if you can. You don’t have very much time to jab him once he’s in the chair. If you don’t hurry, he’ll hop out again with full health and you’ll have to do that phase over again.
After you drain him for the fourth time the fight will end. There’s two possible endings to the game, depending on how you treated the little sisters throughout the game. I won’t spoil them for you, but try to check them both out if you can. You will also earn the “Defeated Atlas” achievement for 100 GP.
