The Rogue by Trudi Canavan

Kyralia is facing threats at home and abroad, as a rogue killer stalks its capital's streets, while the neighbouring kingdom of Sachaka is breeding a rebellion that could destabilise the entire region.

High Lord Akkarin and Sonea's son Lorkin has a legacy of heroism to live up to, but despite his good intentions, his incarceration in Sachaka's rebel Traitor stronghold could destroy the tenuous peace between the two countries. Angered by Lorkin's seeming defection the Sachakans blame the Kyralian ambassador, Danny - and they are a savage people when roused.

And back home, in the University, two young novices are about to remind the Guild that sometimes their greatest enemy comes from within . . .