Knives in Tenebris Somnia — The Lapis Fictus → Aurifer Chain

Knives in Tenebris Somnia are not standalone weapons. They form a four-step forging chain that ends with the Aurifer Knife — the relic that decides Good vs Bad ending. Each knife replaces the previous one in the chain.

1. Lapis Fictus Knife — replace the knife on Iván's Floor 2 statue with a blue crystal knife.
2. Melanosis Knife — feed the Lapis Fictus into the kitchen fusebox.
3. Virdis Knife — feed the Melanosis Knife into a mercury puddle in the kitchen area.
4. Aurifer Knife — feed the Virdis Knife into the locked Hotel door symbol. This is the relic used to decide Good vs Bad ending.

Lapis Fictus Knife

1. Back in Iván's living room on Floor 2, find the Iván statue holding a knife.
2. Use the Auritsatio spray on the statue to replace the blade with a blue crystal knife.

Melanosis Knife

1. Exit the apartment.
2. Use the Lapis Fictus Knife on the fusebox in the kitchen (reached via the bathroom hole in the broken wall).

Virdis Knife

1. Sprint through the Relicta ghost corridors using the Ladder to descend.
2. Use the Melanosis Knife on the mercury puddle in the kitchen area.

Aurifer Knife

1. In the Studio Lobby, use the Lead Key on the symbol door.
2. Walk north through every door to the locked Hotel door.
3. Use the Virdis Knife on the Hotel door. The Aurifer knife is granted at the cutscene.

After the Aurifer is collected:

• Don't kill Relicta ghosts → SOLVE ET COAGULA (Good, Lacuna).
• Kill Relicta ghosts on every floor with the Aurifer (not just on the path to Séptimo Arte) → MAGNUM OPUS (Bad, Hermes) and the Heart of Lead count.

The Aurifer is the only weapon that hits Relicta ghosts. The full sprint route and Aurifer branching is on the endings page; the full walkthrough page covers the Lapis Fictus → Melanosis → Virdis → Aurifer sequence in context. The Devoured achievement (walk into Hermes' mouth during Ending #2) is on the achievements page.