A sequel to The Sword of Culann (1973) in which Claudia and step brother Evan again penetrate 20th century Maine mist to the past--here the Orkney Islands of the 7th century. Again the children become onlookers and, intermittently, participants in rumbling confrontations among great, glowering warriors; the tinder box conferences of rulers; flights and routs. Although the central movers here do not reach quite the fiery stature of Fergus or ""The Hound"" of the previous book, there's an ancient Princess of Erin and her serpentine king-making; a brooding Viking oppressed by his own moral judgments on death and destiny; an insidious Sidh who just might have walled up the children in time; and the mute waif Nessa, a Pict, who could have evolved from the ""seal people."" While Claudia watches Evan become increasingly enthralled by Nessa (one of the story's strengths is the balance of tensions to which the prickly relationship between the children contributes), the three move in and out of the struggles between proponents of the religions of Christianity and Odin, North men and ""Irish,"" and the quests of a monk and a ballad singer who would recover the relics of Culann. The tangle of plot and symbols, magic and plausible historical events is well nigh impossible to follow. The supernatural talismans--the sword hilt, scabbard, sun stone, etc.--all seem to smoke at the edges, vanish and reappear again at two time levels. The blizzard of unfamiliar names and places and legends continues unabated. However, apparently what Ms. Levin has attempted is a sacrifice of crisp clarity for an atmospheric montage of a time blood-dark in superstition, shifting cultures and dreadful allegiances. Appropriately, the children are for the most part damp, uncomfortable, apprehensive, wary of danger. Even a brief 20th century hiatus in which Claudia attempts to feed Nessa orange soda (Nessa who knows better, spits it out) does not change the air of menace. For the agile mind, an unusual adventure in time travel--but prior familiarity with The Sword of Culann is advisable.