A first novel worth making some allowances for: dig under its stuffy tweed; resign yourself to its Beacon Hill/Harvard boundaries; and forgive the slightly over-contrived parallels of its narrative energies. If you can do all that you'll find that this fiction debut--about a past that looks readily understandable but is actually missing a piece--has a certain grace. Isobel Storer is 72 when her granddaughter Robin's boyfriend, David, a junior prof at Harvard, begins drafting a biography of Curtis Trevelyan--a well-bred writer, turned radical by the Sacco-Vanzetti case, with whom Isobel had a secret, adulterous affair in the late Twenties. Working from letters and diaries in Isobel's possession, David is none too fast in unearthing and making the illicit Trevelyan/Isobel connection; that is mostly left for Isobel to remember privately, her looks backward incomparably more graceful than the present-day problems of David and Robin--whose love must be navigated through the deeps and shallows of Kent State, the Harvard strike, the Cambodian bombing. Moulton, too, when writing about brave young Isobel (married to an industrialist, loving a populist), imagines the moral dilemmas of the Twenties more acutely than those of the Seventies, toward which she's indulgent, even a touch condescending. So this demurely ambitious novel doesn't really work as a double reflection of political unrest for two generations; and the proceedings now and then do drift off from quiet into downright sleepy. But Isobel is a sturdy character creation, and her complex, starkly remembered socio-political history offers some graciously served food-for-thought. An unexciting but steady debut.