Polly Solo-Miller Demarest has all that she always expected to have: ""a husband, two children, a strong family, and a month's summer holiday in Maine. Once she was married, her life had been so accomplished that all she had to do was live it. But it turned out that life was not a straight path. You woke up on the wrong side of the law with the right set of feelings."" That wrong side of the law is represented here by Lincoln Bennett, a painter with whom Polly has been having an inextricable affair--one that goes against the grain of her upbringing (among the rich, Jewish, very correct, and close Solo-Millers), of her love for lawyer-husband Henry. And, though the family is a haven and fidelity is a spine in a life that's otherwise treacherously jellied: ""What did a smoothly run house, good meals, sweet children, and an admirable husband matter if you felt your heart being torn to pieces?"" Such is Polly's quandary--and it's fleshed out with some of Colwin's most heartfelt prose: the mix of pain with authorial breeze and social-antenna perceptiveness is occasionally quite spectacular in terms of tone; there are fewer jokes than in Happy All the Time, though some of the comic description is inspired (an after-dinner pianist ""played exclusively as background, but the expression on his face was that of an ingenious veterinarian who had quelled a room of anxious schnauzers""); and Colwin's drumming insistence on the conflict between (and complexity within) personal and family happiness gives this novel more than a little Russian flavor--Chekhovian intimacy, Tolstoyan responsibility, longueurs and passions. So, though the ruminant theme announced in the title flattens some of the feeling here (Polly's agony comes across only fitfully, the hurt and confusion muted by the author's nervously churning reflections), Colwin is to be credited for having gone beyond the mere charm of her previous work. And if the ingredients for emotional combustion never quite explode in this richly ambitious novel, they are graceful, unsimplified, very often strikingly--and fully--stated. An impressive step forward for an increasingly serious entertainer.