The Language of Ghosts by Heather Fawcett (review)

Noa learned the hard way that it's not easy being the Dark Lord's little sister: as big brother Julian schemes to acquire power and regain his stolen throne, he leaves a trail of broken hearts (male and female) in his wake and pays more attention to tutoring their magically gifted younger sister, Mite, than to implementing Noa's sensible suggestions. As Julian's sorcerous behavior becomes increasingly disturbing, Noa worries that she'll lose the brother she loves. When the siblings get word that usurper Xavier is after two books of lost magical languages to expand his power, the race is on for magical and political supremacy. Noa's a likable heroine; readers will roll their eyes in sympathy at the sibling shenanigans she has to put up with and cheer as she comes into her own. Fawcett's magical system is intriguing: magical languages give those with inborn affinity power over worldly elements like seawater and earth, or metaphysical elements like death and fear, and those who can speak more than one are considered dark magicians. Amid floating islands, invisible cats, and cake-based plot points, there are blink-and-you'll-miss-it discussions of political systems that encourage people to act against their own interests to ingratiate themselves with their oppressors. Primarily, though, despite Julian's worrisome penchant for throwing people to the sea monster and the siblings' lingering grief for their dead mother and lost home, it's an enjoyable, light-as-air romp that satisfies while leaving enough unfinished business for a potential sequel.