The Warlock's Child Series by Paul Collins, Sean McMullen

An exciting fantasy-adventure series by Paul Collins and Sean McMullen.There is no lower rank than cabin boy on the warship Invincible. But Dantar knows he is important, because anyone who threatens his life gets turned into a pile of ashes. His older sister Velza is a shapecasting warrior, in a world where only men fight. Until now. Together they must solve the mystery of broken magic and escape the dragon.

A collaboration by Paul Collins and Sean McMullen, two of Australia’s most popular fantasy authors. The Warlock’s Child weaves a new and exciting brand of magic.The Invincible has been attacked, and all seems lost. Dantar’s only escape from his enemies is through the foul-smelling sewers of Savaria. Velza’s plans to save him are soon thwarted by three enormous dragons threatening to set fire to the city. Can Dantar and Velza deliver the city from danger?