The Irish-born Princeton professor dazzles the ear with his eighth book of verse; full of inventive rhyme and repetitions, and seamless meters, Muldoon's work resembles the monk of his poem ""Anonymous"": ""sharp-witted, swift, and sure."" A linguistic voluptuary, Muldoon sometimes leaves readers behind with his gestures to Apollinaire, and his dense Joycean patter; but his best poems ground his visionary sensibility in everyday observation: ""The Mudroom"" and two poems titled ""The Bangle,"" in particular, rely on a collage of imagery and idiom, from Yiddish slang, Asian clarity, and classical allusion to the common items found in a mudroom (hubcap, extra fridge, soft drinks). Muldoon's playful wit supports one virtuoso piece after another: a bit on the famous Siamese twins, Chang and Eng (""Lag""); a mess of fractured aphorisms and proverbs (""Symposium""), and a versified errata sheet. Less successful are his calligrammes (and other visual jokes), as well as a long sequence inspired by rock records--a forced set of personal liner notes recounting memories associated with particular albums. The ninety rhymed haiku of ""Hopewell Haiku"" are wonderfully anecdotal and properly spare--Muldoon holds his expansive humor in check. Throughout here, he plays on his name and returns to the simple image of his title: the one thing he knows with certainty. When he eschews cleverness for its own sake, Muldoon enlists his considerable technical skill in undermining his own conceits: he's clearly a major young poet in any case.