Hidden Jewel has 373 pages.
The Jewel in the Skull has 175 pages.
The Jewel of Medina has 432 pages.
The Jewel That Was Ours has 224 pages.
The Jewel of Seven Stars has 337 pages.
Hidden has 160 pages.
The Hidden - Animorphs - has 121 pages.
The Hidden Universe has 134 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.