The Commissioner of New York City Landmarks (historian Moore) and a senior editor of Essence (Johnson) team up for a biracial Christmas story about white St. Nick and black Pete, who stand side-by-side atop Terrence's Christmas tree in Harlem. Terence, now married to Cassandra, was only seven when his silver-haired grandfather took him on as copilot of his city bus on its 12-mile route and related to the boy the history of various African, Indian, and Dutch landmarks, especially those--such as St. Nicholas Avenue--tied to blacks. Terence, raised in black culture with Miles Davis's ""Sketches of Spain"" playing in the background, has attended Lorraine Hansberry's A Raisin in the Sun. His mother is a librarian at the Countee Cullen branch of the New York City Library. Grandfather still mourns his wife's death and doesn't attend family functions. As Terence discovers, St. Nicholas was born 1,600 years ago, while Pete, born a slave in Spain under the Moors, was a kind of all-purpose genius who earned his freedom at 18, went through various occupations and studies in Seville, and (during the Inquisition) fell in with St. Nick--who had been imprisoned as a spy. Pete, his jailer, helped him escape and joined him as an equal partner, eventually coming to New Amsterdam. Now Pete's genius is put to good purpose in helping Nick provide gifts to the needy. A mind-expander, perkily illustrated by Julie Scott's woodcuts.