Crimson Thunder has faced assassins, rogue shifters, corrupt masters, and creatures that never should have existed.

Now he faces something far worse.

The Earth itself is beginning to fail.

Ancient sites are dying. Weather patterns are shifting. The hidden Sentinels responsible for maintaining the planet’s ecological and mystical balance are losing power, and no one knows why. If the imbalance continues, the consequences will spread far beyond the shifter world.

The High Court gives Crimson one order: fix it.

But Crimson quickly discovers the crisis may be tied to crystals disturbed deep beneath the Earth—crystals shifters were never warned not to touch. Refusing to solve another ancient problem with half the truth, he forces dragons, bears, scientists, and Sentinels to work together before the damage becomes permanent.

While Crimson fights to keep the world from breaking apart, Sapphire Thunder is being pulled toward a mystery of his own.

A strange flame-shaped mark has appeared in his palm. It grows stronger near a hidden valley where the mist shifts, the land seems alive, and an ancient place has been waiting for him.

The Library of Shadows.

There, Sapphire discovers Gorrow, the Eternal Flame, and a power tied to his bloodline that may hold answers no one else can reach.

At home, Crimson and Nyla are raising their triplet sons while old relationships begin to heal, lost love gets another chance, and the new shifter order Crimson helped build faces its first true test.

Protecting his people was only the beginning.

Now Crimson Thunder must protect the world they call home.