Though the period and the themes are those of the Vietnam era, a more perennial and primordial war--that between a mother and daughter--dominates this latest novel from Spencer (Jack of Diamonds, etc.). The times are the 60's and early 70's, and the settings range from North Carolina to Montreal to Vietnam, but the one constant is the relationship between Mary Kerr and her mother, Kate. Mary, a talented young dancer and gentle child, loves her father best, and when he dies of a heart attack, her mother as usual blames her. The two women move into a smaller home; Mary continues at school, resumes her dancing lessons (a concession from her disapproving mother); and Kate, a scientist, works on secret defense-related projects in the lab of the local university. One summer while staying with Kate's family (except for granny, all stereotype rednecks), Mary meets Jeff Blaise, a young activist increasingly involved in the antiwar movement. Jeff and Mary fall in love, which angers Kate: she not only disapproves of Jeff's politics but is sexually attracted to him. Then, as antiwar protests escalate, Jeff becomes even more involved, Mary continues to dance, and Kate marries the wealthy Fred of Philadelphia--but she can never let go of Mary--or Jeff. Fleeing the draft, the couple head for Montreal; a daughter is born; Jeff disappears; and Mary's attempted suicide gives Kate another opportunity to interfere. Still obsessed with Jeff, Kate makes Fred track down the hiding Jeff, and then has him sent off to Vietnam--with predictable consequences. Poor Mary is left to ``dance it out,'' as she always has. Vivid and nicely varied settings, but the politics seem dated, and Kate, the monster mother, remains an enigma--as does everyone else here, though they all talk up a storm and keep diaries. Readable but thin.