A wild epic tale of adventure and magic, as the Morrigan, the goddess of three aspects, returns to the human world, Galway, specifically, ready to wreak havoc and only Pidge and Brigit stand a hope of thwarting her, even though they were only a pair of young children and have no idea how. Nonetheless after a curious encounter in a bookshop, and a pair of strange neighbours take up residence in a nearby greenhouse, Pidge and Brigit set out on a dangerous and thrilling journey into another world in search of the one thing that can defeat the Morrigan. Hunted relentlessly by the eponymous hounds, the children are aided and assisted by a series of strange and sometimes noble and sometimes hilarious characters, many of them straight out of Irish myth and folklore. In fact, this may be the greatest work of Irish children's fiction to use so much folklore so well, or at least the best I've read so far. Much of it is incredibly charming and funny without being twee. Some of it is very strange and solemn and scary, and somehow the O'Shea mixes the different tones seamlessly, without ever jarring the reader, creating an evocative and unreal atmosphere where anything can happen, and probably will.