"Eagle of South, Wolf of North. What can these words mean?"
"The words on the cover, what can it mean? A medal was hidden inside the book."
By opening this book, the Medal of Eagle is uncovered.
The book can be found on a shelf inside Lord Spencer's study across the hall from the Large Gallery. The door requires the Helmet Key to open. On Advanced or Arrange mode, it is moved to a small room inside the Library, where the player would originally find one of the MO Disks.
In the 2002 remake, the book is renamed to "Last book Vol. 1" and can be found in Trevor's tomb beneath the Mural corridor after solving the room's puzzle in which a ladder can be climbed down into the tomb and a grave can be examined within to obtain the book and then examine it to receive the Medal of Eagle.
The book, as well as its twin, were renamed in the remake, originally being called the "Doom Books"