The D'Evil Diaries (Bk. 1)

Twelve-year-old Jinx is hopeless at being evil. Which is a bit of a problem when you're Lucifer's youngest son. But when Jinx runs away from Pandemonium, the walled city he's lived in all his life, he bumps into dead girl Tommy - who's been sent to Hell for accidentally feeding her nasty uncle to a circus lion - and unearths a conspiracy that could up-end the entire underworld.

Cue shenanigans involving carnivorous carousel horses, death-trap-riddled libraries and hungry quicksand. Now the fate of the realm rests in the hands of its most unlikely demon and a girl who shouldn't be in Hell at all...