When four English children are transported through time, via the magic key to an old Scottish keep, they react very differently: back in 1460 Andrew, the eldest, fights bravely to deliver a message to Laird Hepburn and James of the Fiery Face while 11-year-old Elinor merely pouts for want of a hair brush and decent food. Later, amid the 22nd-century ruins of technological civilization, it is Elinor who accepts challenge courageously while Andrew and Ian, eight, are paralyzed with fear. Most affected, however, is five-year-old Olivia who first ""becomes"" the waif-like child of the Hepburn's daughter Muckle-mooth Meg, has to learn table manners and reading all over again when she returns to her own time, and, finally, after a reassuring talk with the future incarnation of her Aunt Grace, recovers some of her own memories and personality. The narrative is strewn with half-realized suggestions: the 15th-century villagers believe the childrens' coming may ""spell the end of an age"" but why or indeed if this is so is never clear, nor is anything made of their nationality which is, after all, the same as that of the villagers' enemies. Similarly the intriguing vision of a new post-industrial culture is conjured up only to be dismissed. The lesson, that the siblings must learn to cooperate to survive, is made all too obvious, but the fragmentary flashes of character and small historical cameos offer appealing, if partial, compensation for the story's lack of a coherent dramatic center.