The Keeper is an entity of nature as ancient as he is perplexing. Unfailingly, he has guarded a grove that his people, a small, peaceful dominion of red deer, have held sacred for many thousands of years, allowing no harm or threat to trespass within its most secret depths. Once more his diligence is challenged when a small incursion of changelings invade his domain, seeking the precious, healing sap at its very heart.

After fending them off with his powers, he discovers that one of them, their captain, had been injured in the struggle and left behind for dead. Taking pity upon her, he brings her into his grove to heal from the wounds and debilitating poison accrued in the scuffle. The battle-worn and tetchy changeling, Cert, is of course incensed at the creature and swiftly begins plotting his demise. But after some events transpire that unravel their pasts and unwittingly tie them closer together, her view on him slowly appears to start shifting in another direction.