You get it from the lady in the hidden village when you show her the domain rod.
The Twilight of Briareus has 255 pages.
Planet of Twilight has 416 pages.
The Twilight of Atheism has 306 pages.
A Caress of Twilight has 441 pages.
Twilight of the Idols has 208 pages.
Twilight Eyes has 464 pages.
Crossroads of Twilight has 704 pages.
Tara of the Twilight has 288 pages.
The Servants of Twilight has 432 pages.
Jedi Twilight has 368 pages.
The Constant Princess has 400 pages.
The Princess of Dhagabad has 272 pages.