The Ian McEwan paradox continues. As before (The Cement Garden, In Between the Sheets), he writes some of the cleanest, most sparely seductive narration this side of Graham Greene. Also as before, what his page-by-page craft sweeps you along to is a virtual dead end: a kinky, symbolic sexual situation which is neither effective as storytelling nor freshly resonant as metaphor. Here he follows an unmarried English couple, Colin and Mary, on vacation in an unnamed, Venice-like city. They are beautiful, bright, liberated, a bit androgynous, and having a mostly miserable time. Then, one night, wandering the streets in search of a restaurant, they meet Robert--a wealthy native (though London-bred) who squires them about, regales them with tales of his childhood (strict training in old-fashioned European sex roles), and spirits them off to his splendid villa. . . where his demure, smiling Canadian wife Adrienne seems to be in constant pain, perhaps a prisoner. Other oddnesses accumulate as well: Robert, who seems at least latently homosexual, punches Colin in the stomach after delivering a tirade on the misery caused by today's sex-role confusion; Mary sees a secretly-snapped photo of Colin on Robert's wall. But the lovers continue--with exasperating passivity (or have they been drugged?)--to hang around with these weirdos. . . until it's too late: Adrienne confesses her sadomasochistic conjugal life (Robert even broke her back); Colin becomes the sex/death sacrifice of the odd couple; and Mary is left to announce McEwan's theme--"how the imagination, the sexual imagination, men's ancient dreams of hurting, and women's of being hurt, embodied and declared a powerful single organizing principle, which distorted all relations, all truth." Plausible psycho-sociology, perhaps--but a thunderingly clunky ending to a novella whose first half promises important fiction. So, once again, McEwan seems to be a huge talent constricted by the need to preach, philosophize, or work out private obsessions; and one can only hope that writing beguiling but disappointing essay-stories like this one will free him to write more wide-ranging, full-visioned fiction in the future.