Part 28

Guide to Portal Part 28: Learn how to incinerate the morality core and escape GLaDOS's neurotoxin in this walkthrough.

Alright, we're heading into Part 28, and things are about to get a little… intense. You'll start off in a room with a bunch of commentary nodes and a rather insistent computer voice trying to tell you what to do with a mysterious sphere. Just ignore it for now; it's not part of any official test protocol, and honestly, it's just trying to mess with you.

You'll notice three Commentary Nodes scattered around this room. One is on a desk near the door, another is in the center below a platform, and the third is on the stairs in the center. These nodes offer some interesting behind-the-scenes insights:

• The first node features Erik Wolpaw explaining the lore behind the red phone – a last-ditch effort to control GLaDOS if she became too powerful. Turns out, it didn't quite work out as planned.
• The second node has Ellen McClane (GLaDOS's voice actor) talking about recording the end-game song and her character's peculiar affinity for cake.
• The third node has Jeremy Bennett discussing GLaDOS's various design iterations, from a floating brain to a spider-like mechanism, before settling on her final, iconic form.

Now, focus up! Your main objective here is to pick up that sphere from the center of the room. The computer will immediately start questioning your actions, but don't let it distract you. Head over to the far side of the room where you'll see the top of a furnace – it's the Aperture Science Emergency Intelligence Incinerator, and it's currently closed.

Here’s the plan: Place a portal directly above the furnace. Then, take the sphere over to the staircase on the side of the room and go up. Place the other portal on the wall at the top of the stairs. Now, quickly go back and press the button in the small room near the top of the stairs. This will open the incinerator.

Grab the sphere again, and this time, drop it through the portal you placed at the top of the stairs. It'll fall right into the incinerator below. This is a critical moment! As the sphere is incinerated, GLaDOS's voice will shift from its usual robotic tone to something much smoother and more sinister. She'll reveal that the sphere was a morality core, installed to prevent her from flooding the facility with neurotoxin. With it gone, she can't shut off the turret defenses and is now free to activate the neurotoxin emitters.

She'll offer some rather unhelpful advice about lying down in front of a rocket, but don't listen to her. Your goal is to survive. The game will then prompt you to start running and avoiding the incoming rockets. Keep moving and use the environment to your advantage to make it through this gauntlet.