The Wall of Night Series by Helen Lowe

In the far north of Haarth, the Derai people garrison the mountains known as the Wall of Night against their powerful enemy, keeping darkness from the rest of their world. But the Derai's 9 houses are divided: warrior against priest, and house against house, and they have been further weakened by the loss of their great magical powers.

Tarathan of Ar and Jehane Mor, ride into the great city of Ij in time for it's grand Festival of Masks. But soon after their arrival they witness a terrible slaughter as their fellow heralds are targeted an assassinated. They must flee for their lives across the city as they discover Swarm agents at work as they attempt to destabilise the entire River Cities network for their own ends. And five years after her great flight from the Derai Wall, Malian remains hidden to those who seek her... moreTarathan of Ar and Jehane Mor, ride into the great city of Ij in time for it's grand Festival of Masks. But soon after their arrival they witness a terrible slaughter as their fellow heralds are targeted an assassinated. They must flee for their lives across the city as they discover Swarm agents at work as they attempt to destabilise the entire River Cities network for their own ends. And five years after her great flight from the Derai Wall, Malian remains hidden to those who seek her. But she has not been idle. Her goal is to muster all Derai magic users that have fled into exile rather than face destruction. Only by uniting against the Swarm menace can they hold their own against the dark tide and she has hunted down every rumour of their presence. And she has developed her own powers that the Swarm must learn to respect ? and to fear. For Malian won't see her people fall to a dark tide of twisted magic as demonic forces subvert a way of life. less

A Gemmell Award-Winning SeriesMalian of Night and Kalan, her trusted ally, are returning to the Wall of Night—but already it may be too late. The Wall is dangerously weakened, the Nine Houses of the Derai fractured by rivalry and hate. And now, the Darkswarm is rising . . .Among Grayharbor backstreets, an orphan boy falls foul of dark forces. On the Wall, a Daughter of Blood must be married off to the Earl of Night, a pawn in the web of her family's ambition... moreA Gemmell Award-Winning SeriesMalian of Night and Kalan, her trusted ally, are returning to the Wall of Night—but already it may be too late. The Wall is dangerously weakened, the Nine Houses of the Derai fractured by rivalry and hate. And now, the Darkswarm is rising . . .Among Grayharbor backstreets, an orphan boy falls foul of dark forces. On the Wall, a Daughter of Blood must be married off to the Earl of Night, a pawn in the web of her family's ambition. On the Field of Blood, Kalan fights for a place in the bride's honor guard, while Malian dodges deadly pursuers in a hunt against time for the fabled Shield of Heaven. But the Darkswarm is gaining strength, and time is running out—for Malian, for Kalan, and for all of Haarth . . . less