Hollow Knight Silksong walkthrough: Part 16 (Exhaust Organ)

Found yourself inside the Exhaust Organ in Silksong? Even by Hollow Knight: Silksong's standards, "Exhaust Organ" is rather a strange name for a region of the world. But it's very apt, in more ways than one. This area is small, but dense with difficulty, and houses a couple of easily missed secrets to boot.

In this quick Part 16 of our Silksong walkthrough, we'll walk you through the perfect route up the Exhaust Organ and its superheated steam-heavy tunnels. We'll also give you our best tips and tricks on how to beat the main boss at the top of the Exhaust Organ, because they could arguably be the toughest of all the Silksong bosses you've faced so far.

Want the walkthrough for a different area of the game? Check out our Hollow Knight: Silksong walkthrough hub!

Exhaust Organ walkthrough steps:

1. Find the cobweb-covered Bench.
2. Pass through the steam vents.
3. Rescue the trapped Flea.
4. Defeat Phantom to unlock Cross Stitch.
5. Activate the Grand Bellway.

Where's the Exhaust Organ map?

Shakra doesn't spawn inside the Exhaust Organ region, so you can't get the map at this point. You can get the Exhaust Organ map from her when you find her in Bilewater. But the area is small and worth doing early, so we're gonna forge ahead without the use of an in-game map to follow. The map for it isn't really useful anyway, so we don't need it.

1. Find the cobweb-covered Bench.

After exiting The Mist, you'll find yourself on a wooden platform near some more worm-infested waters. Head across to the right and enter the building at the end of the path to properly start exploring the Exhaust Organ.

Once inside, head through the short corridor, past the Drapefly enemy, until the room opens up. Climb up to the left-hand ledge, and scale the wall to the top. Here you'll find a Bench covered in cobwebs. Attack the cobwebs to remove them, and then rest at the Bench.

---

2. Drop the elevator down the shaft.

Drop back down from the Bench, and jump over to the right-hand side. Bypass the first way upwards, and take the second one, just past another Drapefly. The tunnel upwards is periodically flooded with steam, so time your ascent well.

There's a hole halfway up on the right you can duck into to avoid the second jet of steam. Mind the spikes above you as you jump from this little nook!

Continue up the next tunnel, and then down the third (watch the spikes at the very bottom). When you get to a crossroads, drop down a very slight distance, and take the left-hand path below. At the end of the path you'll find an old elevator held up by planks of wood. Attack the planks to break them, bringing the elevator crashing down.

---

3. Rescue the trapped Flea.

With the elevator out of the way, jump across to the other side and you'll find a room with a mirror in it. You can play your Needolin here for a bit of interesting lore.

After that, turn around and head all the way to the top of the elevator shaft, and head left, straight through the wall, to discover a secret passage.

At the end of the path is a doorway. Pass through it to appear back outside, above where you were earlier. Follow the platforms over to the left, and you'll find a Flea at the end, trapped in some vines. Break the vines to free the poor thing, and then head back the way you came.

---

4. Defeat Phantom to unlock Cross Stitch.

From the secret passageway entrance, head across to the right, where you'll find more spiked steam-filled tunnels to navigate. At the top, there's some Silk on the right for you to collect if you need it; then cross over and head left into the arena. Here you'll meet the Exhaust Organ's primary foe: Phantom.

Phantom behaves much like Lace did - she's a small, very fast swordmaster (or pinmaster) who attacks with nimble flurries, and can deflect and counterattack to whittle away your health very quickly. She's no pushover. Thankfully, she only deals one damage at a time - unless you get hit by her counterattack.

You can whittle Phantom's health down with tools, of course, although I would spend some time on some "failed" attempts first just so you understand her moveset and what to expect. This is particularly true of Phantom's second phase, in which she starts to very quickly disappear and reappear into her next attack, as well as conjuring large swathes of steam which you'll have to pay extra care to dodge.

The best time to heal is when she flies into the air in order to throw her weapon diagonally down at you. Just dodge the pin, and then heal immediately while she recovers.

I personally had more trouble with the Last Judge than I did with Phantom, but she's still a tough nut to crack. Still, once you have spent time with her moveset, you'll understand her well enough to defeat her.

When you do, Hornet will unlock her next skill - and it's exceptional. Cross Stitch allows you to press RB to deflect an attack just as it lands, allowing you to counterattack with a powerful flurry, just like Lace and Phantom did. Now you know why we went through the Exhaust Organ before Bilewater!

I'd recommend equipping Cross Stitch immediately, learning to incorporate it into your standard attack patterns, and only switching it out for one of the others when the need arises.

---

5. Activate the Grand Bellway.

With Phantom defeated, head left and enter the elevator, which will take you far upwards and outside. From there, head down the path and you'll arrive at a long spike-filled rocky shaft to climb up.

Eventually you'll reach the top, and you can hit the lever on your left to open up a walkway to the next room. There, cross over the trapdoor before you hit the lever to open it. On the left-hand side you can loot a body for a Memory Locket. Then go back and activate the lever to drop down into the Grand Bellway.

There are a few things to unlock here. On your right, you can insert 70 Rosaries to unlock a massive map of the Choral Chambers, which is technically the region you're in right now. To the left, you can activate your first Ventrica - a new system of fast travel through the regions of the Citadel. It currently only takes you to one other closed off location called the Terminus, which has nothing of value to you (yet). But as you unlock more Ventricas about the world you'll be able to fast travel between them just like Bellways.

And speaking of: just a little beyond the Bench to your left, you'll be able to unlock the Bellway for a whopping 120 Rosaries, and see your old pal Bell Beast again. If you have the Rosaries you should unlock all three immediately, but if you have to prioritise, choose in this order:

1. Bellway
2. Choral Chambers Map
3. Ventrica

Prioritising the Bellway means you can easily travel back to good Rosary-farming areas like Greymoor and Mosshome, in order to gather enough Rosary Beads to unlock the others.

The last step for now is to head on to the left, past the Bellway. This is the point where the Act 2 opening cutscene would play, if you hadn't already triggered it by beating the Last Judge in the Blasted Steps. There's an extra step in store for you here though; if you take a few more steps forward after the cutscene ends, then a familiar face arrives: Lace.

Lace will taunt you for a bit, and Hornet will deliver some phenomenal lines in response. But no rematch takes place; at least, not yet. Instead, Lace leaves, and a few new enemies will appear to attack you. After dispatching them, it's probably best to head back into the Grand Bellway for now. Exploring the Choral Chambers properly can wait.

Lace can deliver this same speech elsewhere too...

If you continue along the path beyond the Last Judge, it'll take much longer, but you'll eventually arrive at a point in the Choral Chambers where Lace will arrive and you'll have the exact same conversation. So if Lace doesn't arrive as you exit the Exhaust Organ, don't fear - you're not missing out on any content. You'll catch up with her later.

Join us in Part 17 of what is fast becoming our largest walkthrough ever, as we start to properly explore the Citadel's Choral Chambers.