John Flanagan 
Brotherband 2 [EPUB ebook] 
The Invaders

Eight boys are about to take on a crew of fifty cut-throat pirates . . . is this an impossible quest? Hal and the Heron brotherband are on the trail of Zavac and his precious cargo. Will they be able to find the pirates when the weather clears? And when they do, how can they possibly beat the mighty Raven and its crew of vicious cut-throats and killers?A chance discovery will lead them to their prey, but the pirates have a well-fortified position. The Herons must drive out the invaders – and to succeed, Hal will need to devise a foolproof plan. In the icy waters of the Stormwhite, the smallest mistake could prove fatal.Enter a world of wolfships, epic battles and treachery in the cold northern seas. Enter the world of Brotherband.