The Twin Tome, written in Japanese as Gishiki no Sho: Futago (Ritual Book: Twins), is an old book found in Fatal Frame II: Crimson Butterfly. The tome is one of five important books collected in the Master's Room in the Kurosawa House. In particular, the Twin Tome describes the importance of twins in the village, and their purpose of "becoming one" through the Crimson Sacrifice Ritual.
The Twin Tome and its associated books are used to solve the Tome Puzzle in the Master's Room to obtain the Light Key. The specific word used within this tome is "Sacrifice (贄 Shi)," and it is highlighted in red.
- "In the Crimson Sacrifice Ritual, the Shrine Maidens become one again,
- they become a deity and appease the ✱.
- The latter stays here, watching over the human world.
- The first shall pass through the ✱, calming the earth."