Maggie Blue and the Lost Child (Maggie Blue Trilogy, Bk. 3)

The world has become dominated by climate disasters, wars are breaking out around them between the surviving people and the witches. Maggie has a single quest she must fulfil, but at what cost - to her and her friends, Hoagy, the irascible talking cat, Joan and Ida, Oz and the umons, who are desperate to save her? As the portals between the Dark World and her world start to crumble one by one, Maggie faces a terrible choice - to save herself and her friends or to sacrifice everything she has for the sake of the Dark World. 

Perilous and exhilarating, the last book in the Costa-shortlisted Maggie Blue trilogy comes to a hair-raising climax...