The Hollow Floor 3 Puzzle Solution: The Demonology Grave Lock Code

Solution verified October 25, 2026 against multiple completed runs (TechWiser, Aprasi and IGN walkthroughs). The method is constant; your gravestone values are not.

Floor 3 of The Hollow hub is the Demonology floor: a randomized maze patrolled by the Biter, with a hidden puzzle room holding a coffin, a Grave Lock, and eight gravestones. Solve the lock and the coffin hands you the Third Night Relic — the item that becomes the Festering Felix UGC reward once you escape. Here is the full solution, step by step.

Step 1 — Reach Floor 3 and Enter the Maze

Take the elevator to Floor 3. The floor's layout rerandomizes every time you restart The Hollow, so any coordinates you memorized last session are void. Your objective on entry: explore until you find the puzzle room.

Step 2 — Find the Demonology Puzzle Room

The room spawns in random places — community runs have found it near the theater-style room and in the room with four posters on the wall, but the reliable tell is the vibe: an ancient, spooky room with gravestones and a coffin in the center. Sweep every corner of the maze; there is no shortcut to its spawn.

While you search, mind the Biter — the Demonology floor's monster. It patrols the maze, and getting caught sends you back. Stay along walls, listen, and break line of sight early (the Biter survival guide covers the patterns).

Step 3 — Read the Hint Poem

Inside the puzzle room, before touching the gravestones: from the entrance, walk forward and look right — a big paper on the wall holds a poem. It states the rule the code follows (the youngest at death). Reading it first means you know exactly what to collect from the stones.

Step 4 — Read All Eight Gravestones

Eight gravestones ring the room. Each carries three pieces of information:

• A picture — one of: Broom, Ghost, Witch's Hat, Bat, Spider, Cauldron, Pumpkin, Scared Cat
• A person's name
• A birth date and a death date

Critical: these values are randomized per player and change every restart — any code list posted online for "this week's code" is worthless to you. What you need from the stones is arithmetic, not the values themselves.

Step 5 — Do the Age Math

For each gravestone, subtract the birth date from the death date. The result is the age at which that person died. Write all eight ages down next to their pictures. From one verified run, the ages looked like this (yours will differ):

Step 6 — Build the Code: The Three Youngest

The Grave Lock's password is the pictures of the three gravestones with the smallest ages at death, in order from youngest to oldest of those three. In the example run: Scared Cat (39), Ghost (41), Spider (42) — so those three pictures, in that order, opened the lock. Do the same with your eight ages: sort them, take the lowest three, remember their pictures and their order.

Step 7 — Enter the Code and Take the Relic

Enter your three-picture code into the Grave Lock on the coffin. Correct code: the coffin opens and you receive the Third Night Relic.

Step 8 — Escape and Claim Festering Felix

You are not done: carry the relic back through the maze (the Biter is still patrolling), reach the elevator, and descend to the lobby. There, the Third Night Relic converts into your reward — the Festering Felix UGC head accessory and its badge. The full reward chain is in the rewards guide.

Common Failure Points

• Copying someone else's code — values are per-player; only the method transfers.
• Skipping the hint poem — the paper states the rule; the room gives it to you for free.
• Reading only some gravestones — you need all eight ages to know which three are youngest.
• Dying on the way back — the relic run is the dangerous leg; save your sprint for the elevator.