Louis Holland's father is a bemused left-wing historian, his mother a frustrated social-climber; his sister Eileen is a woman of picturesque self-absorption who takes off for business school in Boston. Louis, bespectacled, bland and prematurely balding, is a radio buff. A series of unrelated events--the mother's inheritance of $22 million, Louis's landing a radio job in Boston, among others--brings this commonplace, unhappy family together at the center of myriad transformations. "Strong motion" refers to the ground-shaking of earthquakes; mysteriously, Boston is being racked by them. As it turns out, the inherited money is tied up in a company that Louis's girlfriend Renee, a seismologist, suspects is causing the disturbances by injecting toxic waste into wells. In an accidental but fateful confrontation, Renee makes derogatory comments about an anti-abortion group's leader. The interweaving of women's reproductive rights issues with environmental disaster places the author (as well as the characters) on shaky ground. Such complicated themes, sounded against the backdrop of a lightly sketched Boston, seem poorly served by having one family heroically sort them out. After the stunning perfections of Franzen's first novel ( The Twenty-Seventh City ), this second effort is a paler achievement. Though his descriptive gifts are still in evidence, the plot becomes an all-too-obvious untying of a highly improbable knot.