Verified answer

this and the 2 customer reviews at the link are all i can find to help you

A creature under the hay. . . a poisonous cake that disappears. . . spots in television sets. . . . It's all trivial business as sorcery goes, and even when the evil woman whom kind old Miss Hepplewhite identifies as King Arthur's sister Morgan shows up as a local rich man's new wife, influencing him to steer a superhighway through the village, her ploy is not a new one for fictional British witches. (That's only one of the parallels between this and Beachcroft's unmemorable Well Met By Witchlight [1973] - which is not to accuse Lively of imitation but only to point out the commonplace nature of her plot.) The three children William, Susie, and Martha have somehow evoked Morgan by cooking up a witch's brew (from Macbeth) in an old barn, but why she pursues them so relentlessly - kidnapping little Martha, following the three young pedestrians in a driverless Rolls - is never considered. Which makes for a lot of gratuitous shrieks, vapors, and transformations, with none of the resonant tension of Lively's best.