Metis's Tome is a unique item in Fire Emblem: The Sacred Stones, found only in the desert of Chapter 15: Scorched Sand, using this scroll on any character will increase their growth rates by +5%. It is most useful on low level units like Myrrh or the Trainee units. It is similar to the Fire Emblem: Rekka no Ken item Afa's Drops.
In Greek mythology, Metis, whose name means 'wisdom,' was a titaness and one of Zeus' many love affairs. When Metis became pregnant, Zeus heard a prophecy that if Metis gave birth to a son, the child would be more powerful than Zeus. So, Zeus swallowed Metis, who then gave birth to Athena, the goddess of wisdom, inside Zeus's head. Zeus, suffering a headache, asked Hephasteus, the god of the forge, to hammer open his head. Athena sprang out, fully grown and clothed with her armor.