Deltarune Chapter 4 Secret Boss Location & Mike Room Code
Deltarune is a spin-off of the acclaimed game Undertale. In its latest update, two new chapters have been added, along with numerous secrets to discover. In Chapter 4, you can unlock a hidden boss by playing a specific tune on the golden piano. To perform the tune, you’ll need to collect three music sheets. Below, you’ll find the locations of each music sheet as well as the secret boss encounter.
Deltarune Chapter 4 Secret Boss Location
The secret boss of Deltarune Chapter 4 can be found in the Dark Sanctuary Library. Next to Jack, you’ll see an old man sitting in the library who closely resembles Gerson from Undertale. Behind him is a fireplace displaying a picture titled “The Legend of the Magic Axe.”
Note: Climbing Gloves are required to find the music notes.
This old man is the secret boss, and the entrance to his boss fight is hidden behind the fireplace. The secret door will appear once you’ve played the golden piano. To unlock the piano, you must backtrack and collect three music sheets. Their locations are as follows:
- First Music Sheet – Found in the area where you first meet the old man, and he asks to have tea after turning on the light. Look towards the left side to find the music sheet. In case you have missed it, the room is located behind the waterfall. The find the waterfall, climb the stairs on the left side of the Old Man Library. Enter the first room and then enter the room on the left side. Here you will find multiple bookshelves, go towards the left side to find the waterfall.
- Second Music Sheet – Similar to the path you took to find the first music sheet, reach the area down the stairs with two bookshelves, and instead of going left, take a right from the two bookshelves. Keep going till you find a climbable tower to reach the dark room. In the dark room, explore and head to the upper-right corner where you’ll see yellow rings of light. Interact with them and continue upward to find the golden switch on the ground. Stand on it to reveal the second music note.
- Third Music Sheet – Go towards the left side outside of the Old Man Library. Pass the first blue piano and then go towards the south. In the next screen, go right down the stairs till the next room, and you will reach two bookshelves. Then go towards the left, and you will find a prophecy that says “The Pointy-Headed will say Toothpaste,” and then “Boy“. Keep following the path till you step on the switches that light up the place and escape the enemies.
On the left side, you will find a climbable wall that you need to climb till the stop by dodging the water falling from above. At the top, you will have to battle with a water dispenser to get the music notes.
Once you’ve collected all three music sheets, go to the golden piano in the study and play the tune according to the notes you’ve found (or as shown in the image above). After successfully playing the melody, a secret door will open behind the old man, revealing a hidden room in the library. Enter the room and interact with the magic axe to begin the secret boss fight.
Mike Room Code
In chapter 4, you will find a building with a TV on it, and inside the building, you will find a room called the Mike Room. The enter the room, you will need a four-digit code, which is 6453.