Ottilie Colter and the Withering World — Rhiannon Williams

SLEEPER COMES FOR NONE
Ottilie and her friends are members of the Narroway Hunt, a secret organisation that trains children to kill bloodthirsty monsters called dredretches.

Now, the huntsmen are under attack â€" by something far worse than dredretches. A witch is cursing them one by one, making them unwilling participants in a vengeful scheme. But what, exactly, is she planning â€" and will Ottilie have to join her to find out? 

The thrilling conclusion to a much-loved trilogy about friendship, changing loyalties and never, ever giving up.