The wizard children, ordinary New Yorkers at the start, are Fionna McCool, eleven, and her eight-year-old brother Bran, both dumped for the summer at Uncle Rupert's New York State country home while their Ma, Sadie, goes off to LA on an acting job. But Uncle Rupert himself is off in Ireland teaching Celtic heritage at Trinity; and the two Irish women he has hired to care for the children seem distinctly odd. Then, in the woods, Fionna and Bran meet the strange boy Deimne, who says the two women, a Druid and a warrior, have raised him to grow up and avenge his father. As he's just turning 17, the time has come. Deimne, mysteriously, must ""reach Temhair by Samhain,"" and ""has much to learn along the way."" And so begin the Wizard Children's adventures, for they too are somehow transported with him to the forests of ancient Ireland. As they travel with him, Fionna becomes his poet and Bran, with his good memory, the reciter of their hero's high deeds. For Deimne along the way--between vanquished monsters and rivals and enemies--is renamed Finn; and when they do reach the castle of Temhair at Samhain (the equivalent of Halloween), Finn performs his bravest deed to date and is rewarded with his rightful leadership of the Fianna. The children mostly tag along throughout, with Bran admiring Finn's bravery and Fionna threatening to vomit from the sight of rolling heads; and as Samhain ebbs they are whisked home as you knew they would be. There are some nice touches--such as the exchange of Fionna's Adidas for another girl's beautifully carved comb; and, for those who catch it, a closing hint as to the children's paternity--but the early, state-side business seems silly and rigged, and the Irish adventures are less than thrilling--more a childish game of adventure. As such, they're entertaining enough.