“It seemed to be one of life’s wonders,” observes Sherwyn Sexton, the not wholly unlikable cad at the center of Fay Weldon’s lively if sometimes frustrating new novel, “Before the War,” “that nothing happens and nothing happens and all of a sudden everything happens.”

And then there is the appendix. You have turned the last page of Lucy Ives’s intricate, darkly funny debut, and a curious timeline appears. Have you missed a plot point or two or 10?

Everything changes for 12-year-old Samantha McGinty in the summer of 1969. Her father, Brick, stops fussing over his Chevy each weekend, no longer spritzing the windows with water and vinegar and wiping them clean with old pages of the Erietown Times.