Ice — David L. Dawson

The cold is coming.
The shadows will win.
Humanity will die.

Cressida and her allies must stand against the Shadow Assemblage one final time. If they fail? Frostma will freeze the planet and the shadow gods will rule.

"Ice" is the third and final book in "The Book of Fire Trilogy", a series of fantasy adventure novels aimed at children aged ten and above, but like Harry Potter can be enjoyed by adults too.