Back to Hollow Knight
To enter the Royal Waterways head to the bottom of the City of Tears and use the Simple Key on the mechanism to open the hatch. Drop down the hatch and you’ll be in the Royal Waterways. You’ll want to buy the Lumafly Lantern before exploring down here otherwise some areas will be too dark to see. Having the second upgrade on the Nail will also help with the Flukemarm boss fight as you can kill the Flukefeys that it spawns with one hit.
From the entrance head to the left and then use the downward smash to break the floor and drop down to the Bench.
Jump back up the wall and continue to the left. Drop off the edge, break the wall to the right and free the first Grub.
Jump back up the wall and then jump and dash across the ledges above the water, dodging the floating enemies along the way. Continue follow the ledges above the water. If you drop down you’ll need to restart the jumps. Once you reach the room to the far left the gates will close and you’ll need to defeat all of the floating enemies before they open again.
Head to the left and hit the lever to open the gate below which leads to the Fungal Wastes. Continue up and around to find Cornifer and purchase a map from him.
Head back to the right, drop down to the water below and enter through the secret wall to the left for a Mask Shard.
Make your way back to the broken Bench. This time drop down to the left. Use Desolate Dive on the hatch to break through to the area below.
Head down, to the right, down and through the passageway that leads to the left with the little worms. You can kill them to fill up your spirit vessel. Break through to the secret passage which leads to the optional boss fight.
The Flukemarm only has one attack. It releases Flukefeys, two at a time. They have 13 health each so if you have upgraded your nail twice you should be able to kill them with one hit.
Stand just to the left or right of the Flukemarm and use the Vengeful Spirit or the upgraded Shade Soul. Kill the Flukefeys for spirit and then cast the spell again. This method works well if you can kill the Flukefeys in one hit otherwise they may swarm you. The Flukemarm has 350 health so it should’t take too long to defeat this boss. Once it’s been killed the Flukenest charm will drop onto the top left ledge.
Make your way back to the broken Bench and then across to the right and then up to the Dung Defender. You’ll hear him shouting when you start to get close.
The Dung Defender has 700 health and three main attacks. He’s a funny boss to fight and not that difficult.
The first attack is the Dung Toss. He’ll roll up dung balls and throw them. They’ll bounce around the arena for six seconds before breaking up. If you have a charm to lengthen your nail then you can hit the Dung Defender while he’s rolling up and throwing the dung without taking any damage.
The second attack is the Dive. The Dung Defender will dive in and out of the dung from one side of the arena to the other. You’ll need to jump over him when he does this.
The last attack is the Burst. The Dung Defender will burst out of the ground throwing dung to both sides. You can hit him when he comes out of the ground and when he drops back down.
Towards the later stage of the fight the Dung Defender will go into berserker mode for about 12 seconds, using the Burst attack over and over again. Once the Dung Defender’s been defeated he’ll drop the Defender’s Crest charm.
Walk to the right and hit the lever. This drains out some of the poisonous water from the entrance to Ismas Grove allowing you to reach that area. The wall to the right can be broken and leads out to the broken lift between the City of Tears and the Ancient Basin.
For now head back the way you came and make your way down to the bottom right side of the Royal Waterways. When you get to the ledge with the crystal formation that’s a clue to use the Crystal Heart and super dash across to the right. You’ll end up going through the lift shaft to the other side.
Continue making your way to the right. You’ll spot a sign from the Dung Defender on the wall. When you get to the small arena and the gates close you’ll know your on the right track. Defeat the Sentries and then drop down to the right. Make your way over the acid and pick up Isma’s Tear. This will allow you to swim in acid.
Drop down to the left and swim through the acid to the right. Jump up the wall to find another Grub. Head up and back to the left. Make your way up to where the small arrow is on the map. This is a shortcut to the City of Tears (East). You can now take this shortcut whenever you want.