The Hidden Universe has 134 pages.
Hidden has 160 pages.
The Hidden - Animorphs - has 121 pages.
Hidden Jewel has 373 pages.
The Hidden Family has 303 pages.
Hidden Ivies has 317 pages.
A Hidden Ulster has 540 pages.
The Hidden Past has 144 pages.
The Hidden Staircase has 210 pages.
The Hidden Hitler has 434 pages.
Her Hidden Children has 189 pages.
The Hidden Child has 400 pages.
Hidden Warrior has 551 pages.