Flight of the Night Hawks - Raymond Elias Feist

Sorcerer Pug wakes from a nightmare that portends destruction for all of Midkemia, and his son Magnus learns the reason: a beacon draws an army of alien invaders, and nemesis Sidi, now Leso Varen. In Stardock town, two boys come of age and go deep into the Empire of Great Kesh. A dark plot implicates the highest-ranking nobles, and the Nighthawks clan of Assassins.