Open season on adultery, that is--as a half-dozen shallow, moody characters change partners, stew guiltily, and talk endlessly in Jackson, Wyoming. Prime stewer/talker is young teacher/carpenter Mark, who's sort-of-going-with dancer Ellen. . . but shies away from heavy commitments because of his ""fear of ending up with a bourgeois life. Fear of not fulfilling some vague sense of special destiny that he'd always carried around with him."" And then Mark meets older, married artist Barbara--who summers in Wyoming with rich husband Rob and kids; the vibes are hot; touches and gazes ensue; after about 100 pages, there's consummation. (""'It doesn't have to be heavy, does it?' she said. . . ."") But, even though the Rob/Barbara marriage is hardly sacred material (there's a visit from actress Kate, Rob's ex-mistress who's really not all that ""ex""), Mark is torn--between his obsessive love and his wish to be good: ""To give her up was to give up something more precious than his own goodness, was to deny what he most deeply felt."" Meanwhile, Barbara feels guilty too--especially after her little daughter gets lost in the mountains and nearly dies. So, when Barbara goes back East, Mark goes back to Ellen, though he's still carrying a verbosely fierce torch for Barbara. (""Why was it so hard to be a decent, civilized person?"") And finally all the characters re-gather for the autumn hunt: the Rob/Kate secrets emerge; the Barbara/Mark affair is exposed (""We're talking about betrayal""); and local guide Tommy, unhinged by the desertion of wife Judy (who was fed up with his infidelities), shoots Mark. . . who now at last, in bandages, is ready to make a serious commitment to Ellen. Stretched out to unconscionable length with hunting, skiing, sculpture-casting, and other outdoors activities: an earnest, pallid successor to Magnuson's similar Without Barbarians (1974).