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Campaign Walkthrough

By ScotUpdated

Tactical Quick Answer

Portal 2's single-player campaign runs nine chapters across three narrative acts: the modern Aperture test chambers, the abandoned Old Aperture shafts, and Wheatley's collapsing facility. Each act teaches its own tools, moving from lasers and Hard Light Bridges to Excursion Funnels and the three Mobility Gels. The game closes with a three-phase boss fight against Wheatley that you win by firing a portal at the moon.

Portal 2 has nine chapters spanning three narrative acts. The game moves from modern test chambers through abandoned 1950s-era facilities and into a collapsing lab run by a rogue AI. This walkthrough covers every chapter with solutions for the major puzzle stumbling points.

info

If this is your first playthrough, try every puzzle yourself before reading solutions. Portal 2's puzzles are designed to be solved through observation, and the writing between puzzles is the best part of the game. Come back here when you are stuck.

Act 1: Modern Aperture (Chapters 1 through 5)​

Chapter 1: The Courtesy Call​

You wake up in a motel-like relaxation vault. Follow the on-screen prompts to look around and go back to sleep. Time passes. You wake up again. The room is wrecked, overgrown, and falling apart.

Wheatley, a personality core on a management rail, finds you through a hole in the wall. He connects to your vault and drives it through the facility like a vehicle, smashing through corridors. When the vault crashes, you step out into the ruined Enrichment Center.

Key puzzles:

  1. Portal gun retrieval. Follow the linear path through decayed test chambers. Orange portals are pre-placed. You pick up the portal device in a ruined version of Portal 1's Chamber 02, and the following room corresponds to Portal 1's Chamber 03. You start with single-portal mode (blue only).
  2. Dual portal device. You receive the full dual-portal device in the Incinerator Room at the end of Chapter 1, which is the same room as Portal 1's Test Chamber 19. That happens before you reach any Chapter 2 test chamber. Walking through the overgrown chamber where GLaDOS was defeated triggers Wheatley's attempt to hack the system, he accidentally reactivates her, and she drops you back into testing.

The chapter is mostly linear. Follow Wheatley, walk through portals, and watch the story happen.

Chapter 2: The Cold Boot​

GLaDOS is back in control and angry. This chapter is denser with new elements than its reputation suggests: it introduces three of them in its first five chambers.

Key puzzles:

  1. Thermal Discouragement Beams (Test Chamber 01). Lasers arrive immediately, in the chapter's very first chamber, not late. A laser fires across the room and a catcher sits opposite. Redirect the beam with a portal pair: one portal in the beam's path, the other on a surface lined up with the catcher.
  2. Discouragement Redirection Cubes (Test Chamber 02). The laser cube shows up one chamber later. Carry it into the beam and angle the re-emitted beam at the catcher.
  3. Aerial Faith Plates (Test Chamber 05). The catapults are a Chapter 2 element too. Step on one and it throws you along a fixed arc.
  4. Cube redirection and flings. Standard momentum puzzles throughout, familiar from Portal 1 but with less obvious geometry.
tip

GLaDOS comments on your performance constantly during this chapter. She is testing your patience as much as your puzzle skills. Her lines are worth hearing. Do not rush through chambers to skip dialogue.

Chapter 3: The Return​

Introduces Hard Light Bridges in Test Chamber 11. Puzzles become multi-step, combining bridges with the lasers and cubes from Chapter 2.

Key puzzles:

  1. Hard Light Bridge traversal. A bridge extends from a wall emitter across part of the room, but not far enough. Place a portal in the bridge's path and another portal above the gap you need to cross. The bridge extends through your portal pair, creating a walkway.
  2. Bridge as shield. One chamber has turrets guarding the exit. Redirect a Hard Light Bridge between yourself and the turrets by placing a portal on the wall behind them. The bridge blocks their fire while you walk through.
  3. Laser cube chaining. Later chambers require two cubes, or routing the beam through a portal before it reaches the catcher.

Chapter 4: The Surprise​

No new test element. Chapter 4 is four laser chambers that push what you already have: Column Blocker, Laser Chaining, Triple Laser, and Jailbreak.

Key puzzles:

  1. Laser chaining. Multiple emitters and catchers in one room, requiring you to hold several beams live at once.
  2. Blocking beams deliberately. Some chambers want a beam interrupted and not connected. Cubes and your own body both work.
  3. Jailbreak. The chapter closes with Wheatley's reappearance and the start of the escape.
note

Excursion Funnels do not appear in Chapter 4, or anywhere in the single-player campaign before Chapter 8. Guides that place them here are four chapters early. Aerial Faith Plates are not new here either, having arrived back in Chapter 2.

Chapter 5: The Escape​

The narrative pivots. Wheatley reappears, badly damaged, and convinces you to sabotage GLaDOS. You go behind the scenes: turret manufacturing lines, neurotoxin generators, and control systems. Wheatley guides you through each sabotage step.

Key moments:

  1. Turret sabotage. You enter the turret production line and replace the template turret with a defective one. Follow Wheatley's instructions. The puzzle is navigating the factory, not solving a test chamber.
  2. Neurotoxin sabotage. Press the button to open the Implosion Observation Annex first, then use a Thermal Discouragement Beam to cut the neurotoxin tubes. There are four tubes and you will need two portal placements, one low-left and one high-right, onto moving panels. Timing those placements against the panel movement is the real difficulty, not aiming the beam.
  3. The core transfer. Wheatley convinces you to perform a core transfer, swapping GLaDOS out of the mainframe and plugging himself in. The transfer succeeds and Wheatley takes control of the facility. GLaDOS is ejected into a potato battery. Wheatley goes power-mad almost immediately and, in a fit of rage, accidentally knocks both of you into the bottom of the elevator shaft.
danger

Chapter 5 ends with a long fall. You cannot prevent it. The fall is scripted and leads directly into Chapter 6. Save before the core transfer sequence if you want to replay the dialogue.

Act 2: Old Aperture (Chapters 6 and 7)​

Chapter 6: The Fall​

You land in the abandoned lower levels of Aperture Science, built in the 1950s. The environment shifts from clean white panels to rusted metal, crumbling concrete, and overgrown test shafts. Pre-recorded audio logs from Aperture Science founder Cave Johnson play on speakers throughout the area.

This chapter introduces Repulsion Gel, the first of the three. The other two arrive in Chapter 7.

Key puzzles:

  1. Repulsion Gel (blue). Blue gel pours from a pipe onto a surface. Walk onto it and you bounce, and falling from height bounces you higher. The puzzle is coating the right surfaces to reach higher platforms. Redirect the gel flow through portals: place one portal under the dispenser and another on the surface you want to coat.
  2. Portalling in an unportalable facility. Old Aperture has far fewer portalable surfaces than the modern chambers, so much of Chapter 6 is about finding the few that exist and building routes from them.
tip

Gel dispensers always pour from above. Look up. If you cannot see a dispenser, it is behind a wall or above a ceiling that you need to portal through to reach. Place a portal under the dispenser's output and another portal on the surface you want to coat.

Chapter 7: The Reunion​

You climb upward through decades of Aperture Science history. The environment shifts from 1950s-era shafts to 1970s facilities to 1980s test chambers. Cave Johnson's audio logs become more desperate as the timeline progresses. GLaDOS (now a potato clipped to your portal gun) provides commentary.

Key puzzles:

  1. Multi-gel combinations. Chambers start combining gel types. Coat a wall with white gel to make it portalable, place a portal on it, redirect blue gel through the portal to coat a distant floor, then bounce off that floor to reach a high ledge.
  2. Gel and funnel combos. Redirect gel through Excursion Funnels. A funnel carries gel drops to surfaces that neither portals nor dispensers can reach directly.
  3. Large-scale traversal. The test shafts in Old Aperture are enormous. Multiple rooms connect vertically. You need to coat surfaces, place portals, fling, and gel-bounce across multi-room puzzles. If you lose track of the objective, look for the exit signs posted on the walls.

Story note: This chapter reveals that Cave Johnson ordered his assistant Caroline to be uploaded into the facility's AI. Caroline became GLaDOS. Potato-GLaDOS reacts to this discovery in real time. The dialogue in this chapter is some of the best in the game. Do not skip it.

tip

Stuck in the Pump Station Gamma elevator shaft? This is mid-Chapter 7, where Conversion Gel is introduced, not the Chapter 6 to 7 transition. Work up the wall with repeated portal pairs, then portal through the elevator floor onto the white side floors, and finish on an angled wall near the top. You place these while standing, so you do not need a mid-air shot.

The Chapter 6 to 7 transition itself is Pump Station Beta, a goo-hazard area of offices and pumps where you reunite with potato-GLaDOS. The really big vertical climb is a third place again, Ascension, at the very end of Chapter 7.

Act 3: Wheatley's Facility (Chapters 8 and 9)​

Chapter 8: The Itch​

Back on the surface. Wheatley has taken over the facility and built his own test chambers. They are poorly designed: panels are misaligned, hazards are placed randomly, and the difficulty swings wildly. Wheatley provides commentary that reveals his growing instability and addiction to the testing euphoria.

info

Expect a difficulty shift. Wheatley's chambers feel less intuitive than GLaDOS's. The visual language changes from "find the white panels" to executing blind mid-air funnel redirects and solving chambers with intentionally broken geometry. The puzzles require different spatial reasoning than anything before Chapter 8. This is by design, not a flaw. If you are struggling, check behind misaligned panels for the portalable surfaces Wheatley accidentally exposed.

Key puzzles:

  1. Broken chambers. Wheatley's test chambers use all the same elements (lasers, funnels, bridges, gels) but with intentionally bad design. The trick is that solutions often involve exploiting flaws in his construction: panels with gaps behind them, misaligned walls that expose portal surfaces, and shortcuts he did not intend.
  2. Frankenturrets. A turret fused with a cube. Walks around on cube legs. Pick it up and use it as a weighted object on a floor button.
  3. Increasing danger. Later chambers introduce real hazards: spike plates, masher traps, and bottomless pits that Wheatley claims are "part of the test." GLaDOS (still a potato) guides you through the worst of it.
warning

Chapter 8 has several chambers where panels shift mid-puzzle because Wheatley is actively restructuring the room. If the room layout changes while you are solving it, that is intentional. Adapt to the new configuration.

Chapter 9: The Part Where He Kills You​

The final chapter. Wheatley drops pretenses and tries to kill you directly. The facility is collapsing. This chapter is shorter but more intense than any previous chapter.

The boss fight:

Wheatley sits in the GLaDOS chassis at the center of a large arena.

Two things have to happen before the fight starts, and neither is optional:

  1. Plug GLaDOS in. Carry the potato to the receptacle. She asks you to directly: "Plug me in, and I'll take you up."
  2. Burst the Conversion Gel pipe. Wheatley's Plan One was "no portal surfaces", so there is nowhere to shoot a portal when the fight opens. Bait a bomb into the white gel pipe overhead and let it coat the floor. GLaDOS points at it herself: "Couldn't we just use that conversion gel? It's dripping out of that pipe there." Until you do this, none of the portal instructions below can be carried out at all.

The loop, which runs three times:

  1. Stun him with a bomb. Wheatley throws bombs at you. Put one portal on the gel-coated floor near the bomb and the other on a hanging ceiling panel, so the bomb travels up into him. The bomb stuns him. It does not damage him. GLaDOS states the sequence exactly: "You find a way to stun him, I'll send you a core, and then you attach it to him."
  2. Take the core she sends. GLaDOS does not build these. She finds them already in the arena, visible in a cage before the fight, and her line on spotting them is "Corrupted cores! We're in luck."
  3. Attach it during the stun window. Look for a blinking red light on his body and reach it by bouncing on the Repulsion Gel. The core attaches itself once you get there.

The arena hazards are deadly pits, bombs and neurotoxin. There are no sentry turrets and no crushers in this fight.

The ending:

After the third core attachment, a stalemate is declared and the Stalemate Resolution Annex opens, a side room holding the pedestal-mounted Stalemate Resolution Button. Press it, and the system initiates a core transfer to remove Wheatley. He booby-trapped it beforehand as the fifth part of his plan, so the explosion blows a hole in the ceiling and exposes the night sky.

The moon is directly overhead. Place a portal on its surface. It works because the moon is made of moon rock, which Cave Johnson's audio logs established as the raw material for Conversion Gel and a superb portal conductor. Your other portal goes on the arena floor. Space does the rest: you and Wheatley are both dragged toward the portal and hold onto the central core body to stay anchored. GLaDOS, back in the mainframe, knocks Wheatley loose first and then pulls you back in.

She lets you go. The elevator carries you up, through an amphitheatre where a choir of turrets sings you out, and then into a shed in a wheat field. The Companion Cube is expelled after you. Credits roll.

tip

The moon shot is not on a timer and there is no documented fail state, so line the shot up properly instead of panicking. Aim at the bright circle in the sky and fire.

General Tips​

  • Look up. Dispensers, gel pipes, and portal surfaces are often on ceilings or high walls. The solution to most stuck moments is a surface you have not checked above you.
  • Listen to the audio. Cave Johnson's logs in Old Aperture tell you what the room is testing. The test name often hints at the mechanic you need.
  • Check behind panels. In Wheatley's chambers (Chapter 8), panels are misaligned. Look for gaps that show portalable surfaces behind the walls.
  • Quick-save before boss phases. Chapter 9 has long gaps between checkpoints. Press F6 at the start of each boss phase.

Frequently Asked Questions​

How many chapters are in Portal 2?

Nine, grouped into three narrative acts. Chapters 1 through 5 take place in modern Aperture, Chapters 6 and 7 drop you into Old Aperture, and Chapters 8 and 9 happen in Wheatley's facility.

How do you beat Wheatley in the final boss fight?

First plug GLaDOS into her receptacle to start the fight, then bait a bomb into the Conversion Gel pipe overhead, because Wheatley removed every portal surface and you cannot shoot a portal anywhere until that gel coats the floor. From there the loop runs three times: stun him by portalling a thrown bomb up into him through a hanging ceiling panel, take the corrupted core GLaDOS sends you, and attach it during the stun by bouncing on Repulsion Gel to reach the blinking red light on his body.

How do you shoot the portal at the moon?

After the third core, the Stalemate Resolution Annex opens with a pedestal button inside. Pressing it triggers the explosives Wheatley planted, which hole the ceiling and expose the night sky. There is no timer on the shot, so take the aim you need. Put one portal on the moon and the other on the arena floor.

Which chapter introduces Excursion Funnels in Portal 2?

Chapter 8, in its first test chamber. They do not appear anywhere in the single-player campaign before that, despite often being placed in Chapter 4. Aerial Faith Plates arrive much earlier, in Chapter 2.

Why do Wheatley's test chambers feel different?

They look slapdash and he narrates them badly, but the chambers themselves are a deliberate teaching curriculum that runs from a funnel introduction through polarity, catching, and laser work. The solutions are intended ones and not exploits of his construction, so look for the designed route instead of gaps behind panels.