She lived where the railway tracks met the saltpan, on the Ahri side of the shadowline. In the old days, when people still talked about her, she was known as the end-of-the-line woman. Vasethe, a man with a troubled past, comes to seek a favour from a goddess who is not what she seems, and must enter the nine hundred and ninety-nine realms of Mkalis, the world of spirits, where gods and demons rage in an endless war. The Border Keeper spins wonders both epic - the Byzantine bureaucracy of hundreds of demon realms, vast yellow oceans, hidden fortresses - and devastatingly quiet - the sizzle of onions and turmeric, a spear flung straight, the profound terror and power of motherhood. What Vasethe discovers in Mkalis ripples back into his own history, which may contain the key to saving everything he holds dear.