Secrets at the Heart of the Lake is a multi-region, multi-chapter spanning quest chain in Phantom Blade Zero, and is essential to unlocking the true, perfect ending of the game. You can make progress on a part of this quest in the Heartless Remnants chapter, while working through the Village of Lu chapter.
In this quest, you get tasked to finding 6 Memory Flowers left by Firefly – who was working with her Senior Brother Dusk. Completing this quest helps increase your total HP, and also get your hands on a missable weapon in the Village of Lu
Here are all the locations for the 6 Firefly Memory Flowers, and the rewards for getting all of those in Phantom Blade Zero. You can get them in any order – what I have put below is the order you will come across them as you progress through the region.
Firefly Memory Flower Location # 1
Take the left exit through the gate with blue-lit lanterns after defeating Zhuo Bi, The Gatekeeper. You will spot a couple of children playing around a Memory Flower. Interacting with this updates the Secrets at the Heart of the Lake to finding 6 Firefly Memory Flower locations – with this being the 1st one.
Firefly Memory Flower Location #2
Start from the Well of Three Puppets bell, and take a right to come to a ledge as shown above, overlooking a stream. Jump down, and go to the left. Clear out the enemies to get the 2nd Firefly Memory Flower.
Firefly Memory Flower Location # 3
Enter the Temple of Blue Fireflies from the bell, and on your right will be the Firefly Memory Flower # 3. Make note of this location – this is where you also progress side quests like A Puppet’s Wooden Heart, and Young Mistress. Also note the mist that you can’t go through at the exit of the Temple. We will be coming here after collecting all 6 Memory Flowers.
Firefly Memory Flower Location # 4
Start from Zhang’s Hideout (Village of Lu) bell, exit past the gate and you will slide down a path. Look to your left for a house with a shrine, and some red threads. Take out the enemies here, and then get the next Firefly’s Memory Flower.
Firefly Memory Flower Location # 5
Start from the Covered Bridge bell, after you have unblocked the Red Threads. Cross it, defeating the spear and shield enemy.
Grapple to the second such passageway, and continue straight, past the fallen tree log, and then take the right before the next set of steps. Defeat the enemies here, and enter the building to take a ladder going down.
Exit out of the building here to get Firefly’s Memory Flower 5. No Word, and a Blackstone Shard if you have not taken it before.
Firefly Memory Flower Location # 6
Start from the Engine Giant Remains bell. Take the climbable ledge to go down a level.
You will emerge out into an open area with a few enemies ahead of you. Clear them out, and look to the left for a tree log that you can jump over. Ahead, you will find the final Firefly’s Memory Flower.
Next Steps After Getting All 6 Firefly Memory Flowers
On getting all 6 Firefly Memory Flower locations, you will get the 10% increase in max health. Also, you can now travel to the Temple of Blue Fireflies, exit from the back, and enter the mist. This will lead you on a linear path to the Broken Puppet Pit Entrance bell.
On jumping down from here, you will get into a fight with Dusk, The Puppeteer. Defeating him gets you the Puppeteer’s Bell Phantom Edge – one of the 7 weapons and Phantom Edges in Village of Lu.
You can use this to summon 1 Sword and Shield puppet, and 1 Spear and Shield Puppet to fight on your side for 15 seconds.
