The Heir of Night is an epic fantasy novel written by New Zealand author Helen Lowe.

In the world of Haarth, there are nine houses of a race not native to the world of Haarth called the Derai, some are allies, and some are enemies, but all with one common, overarching goal: each of these houses works to defend the Wall of Night, a vast mountain range that separates the Derai from their ancient and mortal enemies, the Swarm of Dark.

But unbeknown to the Earl of Night a decision is made that Malian must leave the Keep while she comes into her full power.

She leaves the Keep with the young novice priest that she has now befriended, and her Steward Nhairin and two soldiers to protect her.

The pursuers catch up with them and they find that Nhairin the steward has turned against them, possibly because of a madness caused by the power in the land or maybe by the Dark Swarm themselves.