It might seem like Act 2 is the end of Hollow Knight: Silksong, but there is a secret Act 3 to unlock in the game, too. Before you get to this point, you need to complete the Silk and Soul quest, which requires you to collect 3 different soul types and one item. If you are having a hard time trying to locate all items in the game, keep reading below to know where to look for them.
How to Start the Silk and Soul Quest in Hollow Knight: Silksong
You need to complete everything in Act 1 and Act 2 before you get to unlock the secret Silk and Soul quest. That includes every wish, donation, quest, locating at least 20+ Fleas, releasing the Green Prince, and all boss fights so far. Each wish, request, or quest unlocks while exploring certain areas, so uncovering the entirety of the map will help you locate any missing quests or requests.
If you are done, you should get the option to speak to Pavo in Bellhart, which rewards you with the Bellhome. Also, if you have gathered enough Fleas, all of them, including Fleamaster Mooshka, will shift to the Putrified Ducts. With all this covered, check the Bellhart wishboard to pick up the Silk and Soul quest, then make your way to Songclave in The Citadel to find the Caretaker NPC.
If this NPC doesn’t spawn for you, backtrack across every region to see if you have missed anything.
How To Get All Souls and Items For Silk & Soul Quest
Speak to the Caretaker and indulge their plan to set a trap for the Grandmother Silk. This requires you to locate 3 different souls and one item across the regions.
Maiden Soul Location in Silksong

The Maiden Soul is the easiest of the 3 souls to find, and you can get it at Bone Bottom. While you are within this area, keep going down to the lower levels till you reach the southeast entry point to get to the Marrow. There is a camp here. Just go west of the camp and continue until you spot a lone bug called Chapel Maid.
Speak to her and tell her about your plan, and she will gladly accept your offer and give you her soul. You got one soul down, 2 more to go.
Hermit’s Soul Location in Silksong

Next up is the Bell Hermit’s soul, which is found in Bellhart Bellway. To get here, if you are in Bellhart, head to the bottom and enter the home in the central area, between Shellwood and Greymoor. Once you are inside the tunnels, continue downwards, go east, and continue to go down further.
You will reach the underground section of Bellhart and land at the topmost platforms. Don’t go down any further; rather, continue to go west. You will reach a tunnel entrance, which is home to the Bell Hermit. Speak to him and retrieve his soul, then continue with the rest of your journey.
Snare Setter Location in Silksong

For the Snare Setter Soul, head over to Weavenest Alta after passing through Moss Grotto to find it on a table. If you are at Moss Grotto, then make your way to the bottom of the level and take the eastern exit. The door would be locked the first time you get here, and the only way to unlock it is to collect the Needolin Skill by defeating the Widow and using it here.

Run all the way east and use the portal to get to the next level, then go east and jump upwards using the Clawline skill. Once you reach the top, go west till you reach the section shown on the map above. There is an opening above you here; use it to get to the upper floors. Continue east once you reach the top and collect the Snare Setter from the table.
Seeker’s Soul Location in Silksong

The last location you need to go to collect the Seeker’s Soul is at the topmost section of Bilewater. You would have unlocked the bench here if you had made your run through this area before. Just west of the bench is an abandoned home you could enter, and go through it to find the Seeker’s Soul within some rubble.
Head back to Songclave and speak to the Caretaker to hand over all your collected items and complete the quest. Follow through the rest of the game as usual till you reach the top of The Cradle. The Caretaker will wait for you before the Grand Mother Silk boss arena, speak to him to set the trap, and head in to defeat the boss.
Once the boss is down, don’t bind to Grand Mother Silk. Rather, play the Needolin to unlock the third ending to Hollow Knight Silksong. Head into your save file once more and click on it repeatedly to break the vines covering it, and loading it up will unlock Act 3: The Abyss.