Aphelion: Chapter 3 & 4 Walkthrough – Escape Pod to Onyx Forest

Chapter 3 starts with one of Aphelion’s nastiest little tricks: Thomas wakes up hurt, the cave walls look climbable, and the obvious line forward is usually the wrong one. This Aphelion walkthrough for Chapter 3 and Chapter 4 is the clean route through The Escape Pod and The Onyx Forest: treat both chapters as survival traversal, not freeform exploration. Refill oxygen every time you see a tank, take the intended ledges instead of forcing steep climbs, pull down or set up traversal aids as soon as you reach them, and slow your pace whenever the game shifts into stealth or EM scanner territory.

The big reason these chapters trip players up is that Thomas is not built like Ariane. His injury changes the rules. Aphelion is quietly teaching you that in Chapter 3, then testing whether you learned it in Chapter 4 with geysers, winch points, ledge chains, Anomalies, and a threat you often hear before you properly see. If you respect that slower rhythm, both chapters become much more readable.

Fast rules that make both chapters easier

• Use oxygen tanks as route markers, not just refills. In Chapter 3 especially, the next legal climb is usually near the next oxygen point.
• Do not brute-force vertical rock faces. If a wall looks like a direct shortcut, Thomas usually is not meant to take it.
• Look right before you look up. Several ledge chains begin on side paths rather than the tallest surface in front of you.
• When a bridge or traversal aid can be dropped, do it immediately. Aphelion likes to turn progress tools into return-path safety nets.
• In stealth, speed is not safety. Audio cues matter more than sprinting.
• Pull out the EM scanner when the environment feels wrong. Distortion, strange equipment, or a fuzzy objective area usually means a nearby anomaly or interactable clue.

Chapter 3 walkthrough: The Escape Pod

Your only real job in The Escape Pod is survival. Thomas starts injured and low on oxygen, so the chapter is less about puzzle solving and more about reading the cave the way the game wants you to. The path is fairly linear, but it disguises that linearity well by filling the area with climbable-looking rock that you are not supposed to commit to. If a route demands a long, exposed ascent with no clear handhold chain, back off and scan the sides for a gentler sequence of ledges.

From the crash site to the first proper refill

Push forward through the cave and keep your focus on oxygen before collectibles. There are optional bits players can poke around for, but Chapter 3 is one of the worst places to get greedy because the low-oxygen pressure makes detours expensive. Follow the narrow route through the cave interior, slip through the tighter gaps when the path pinches, and stay alert for the first climb that angles around the rock instead of straight up it. That is a recurring pattern in this chapter: the correct path wraps around obstacles rather than overpowering them.

When you reach an oxygen tank, refill even if you still have some reserve. The efficient habit in Aphelion is to top off early, because the game often places the next traversal test immediately after the refill. Saving a few seconds by skipping a tank is not worth replaying the last few minutes if the next platform chain goes badly.

Rocky ledges, gap squeezes, and the waterfall section

The middle stretch is where most wasted time happens. You will move across rocky ledges, squeeze through gaps, and eventually deal with the cave’s waterfall-heavy section. The safest approach is to think in short climbs. Do not stand at the base of a wall and search for the entire route in one read. Instead, identify the next handhold, the next safe ledge, and the next oxygen source. Aphelion rewards that incremental planning.

At the waterfalls, visibility and surface readability get a bit worse. If the water makes a route hard to read, step back and look for a side angle rather than walking under the spray and hoping the climb prompt appears. The correct line generally stays deliberate and contained, and it leads you upward toward another oxygen refill. Once you reach a pull-down bridge, drop it immediately. Even when the bridge mostly feels like a one-way convenience, it helps anchor your sense of direction in a chapter that otherwise keeps curving through similar cave spaces.

How to read the chapter ending

The end of Chapter 3 is less about execution and more about paying attention. As you push through the final route, the environment starts telling a story through equipment and traces left behind. That organized trail matters. It is the chapter’s big tonal shift, and it explains why the cave suddenly feels less like a random disaster zone and more like a place someone passed through with intent. Once you hit the closing cutscene, the important mechanical lesson should be clear: Chapter 3 was training you to stop improvising and start trusting Aphelion’s authored route language.

Chapter 4 walkthrough: The Onyx Forest

The Onyx Forest picks up immediately after that story beat and broadens the challenge without becoming truly open. This chapter mixes cave exit traversal, environmental hazards, winch use, ledges, Anomalies, and stealth. It feels more hostile than Chapter 3, but it is actually fairer once you realize every obstacle has one dominant idea behind it: timing for geysers, interaction for winches, scanning for anomalies, patience for stealth.

Exiting the caves and crossing the geyser field

The geysers are the first thing that can make players rush, and rushing is exactly what gets you clipped. Watch one full cycle before you move into a dangerous patch. The best time to cross is usually right after a burst, not during the moment it looks like it might be fading. Treat each vent as a timed lane. Clear one safely, reset your view, then commit to the next. Trying to chain the whole field in one smooth sprint is riskier than it looks.

After the geysers, the chapter returns to smaller climbs. Again, resist the urge to take the steepest wall. Follow the ledges that step Thomas across the terrain rather than up it. If the route seems to vanish, check for a side ledge or a point where the path folds back on itself. Aphelion likes layered routes that feel more natural from the side than from directly below.

Winch points and route control

Whenever you reach a winch point in The Onyx Forest, interact with it before wandering off. These points are there to stabilize the route, open the next climb, or create a safer traversal angle. The common mistake is spotting the destination first and treating the winch like optional scenery. It rarely is. If the path ahead looks awkward or too exposed, you probably missed a winch interaction that makes the intended route obvious.

This is also where the chapter starts feeling more investigative. If you have access to a pathfinder-style guidance tool, use it whenever the terrain fans out into multiple similar ledges. The shortest-looking line is not always the legal line, and Thomas’s limited mobility punishes guesswork harder than Ariane’s sections do.

EM scanner use, Anomalies, and stealth

If progress stalls around odd environmental distortion, unfamiliar equipment, or a space that feels deliberately staged, pull out the EM scanner. Chapter 4 uses scanner logic to turn confusion into direction. You are not just looking for a glowing objective; you are using the scanner to confirm that the environment itself is the clue. In practical terms, this means slowing down in strange areas instead of climbing past them. If the chapter suddenly feels less like platforming and more like investigation, that is the sign to scan.

The stealth beat in The Onyx Forest works the same way. The threat is often communicated by sound and tension before you get a clean visual read, so treat it like an audio encounter first. Move in short bursts, stop when the area sounds more active, and avoid the instinct to dash just because you are nervous. Slow movement keeps your options open. Fast movement commits you to bad cover and bad angles. If you fail here, the fix usually is not better reflexes; it is giving the encounter more respect than a normal traversal segment.

The last stretch to the outpost

Once you are through the scanners, hazards, and stealth pressure, the final route to the outpost is mostly about clean execution. Stay disciplined on the ledges, use any last traversal interactions as soon as they appear, and do not turn the closing path into a scavenger hunt. The chapter ends by bringing you into a more structured location, and that shift matters. After all the uncertainty of the caves and forest, the outpost arrival feels like progress in the story as much as in the level flow.

Mistakes that cost the most time in Chapters 3 and 4

• Skipping oxygen because the tank looks “close enough.” Refill anyway.
• Trying to climb directly upward in Chapter 3. The correct path is usually offset to one side.
• Crossing geysers on instinct. Wait for a full cycle and move after the burst.
• Ignoring winch points. If the route ahead feels clumsy, the winch was probably required.
• Forgetting the EM scanner exists. Chapter 4 expects you to investigate, not only climb.
• Treating stealth like a chase scene. Audio discipline beats panic movement.

Best way to think about these chapters

The cleanest mindset is simple: Chapter 3 is about surviving with limited mobility, and Chapter 4 is about proving you learned that restraint. These are not chapters where Aphelion wants stylish improvisation. They are chapters where the game wants measured movement, environmental reading, and calm use of the tools it gives you. If you top off oxygen, trust side ledges, use winches early, scan suspicious spaces, and slow down for stealth, the route stops feeling cryptic and starts feeling deliberate.

Verdict: Chapters 3 and 4 are at their best when you stop trying to outplay them and start reading them. Play patiently, and The Escape Pod plus The Onyx Forest become one of Aphelion’s strongest back-to-back stretches rather than a pair of frustrating bottlenecks.