The Dark Mirror

In the mid 6th century the Pictish kingdom in northern Britain is under threat from the Gaels and the Christian faith, which leaves the leaders of the northern realm struggling to maintain their ancient traditions. All hope rests on the shoulders of young Bridei, a little-known son of the royal line, who is seen as the perfect candidate for future kingship. At his remote forest home of Pitnochie, Broichan, a powerful druid, sets about training the boy in the ways of the ancients and in the all-important preparation to be a leader of men.
But Broichan has not allowed for the Good Folk, inhabitants of the ancient forests of Fortriu and well-known workers of tricky magic. When Bridei discovers a strange baby girl abandoned on Broichan's doorstep in the chill of the winter solstice, he takes her into the house. And the druid has to realise that there is one unpredictable power at work that may be too strong for him to control and could become the death of his dreams.