Elizabeth Bowen, who started out with such authority in the Henry James country to which she refers once or twice here, has now moved into a still more rarefied world. Now certainly she is as curious, cryptic and capricious as Iris Murdoch. So actually is Eva Trout, her oversized and rather outlandish heroine-heiress who disappears unpredictably from time to time, having generated difficulties in between. But then Eva was ""misbegotten"" to begin with--abandoned as an infant by her mother who rushed off to a lover and death, shunted around in a slapdash fashion by her father who was more interested in the homosexual Constantine who becomes her guardian. In changing scenes Eva is seen long enough to become the enzyme of uncertainty and unrest that she is--disrupting the marriage of a former teacher, attracting the youngest son at a nearby vicarage, hovering here, unsettling there, disappearing to reappear eight years later with the deafmute who was ""virtually born"" to her but then is ""not of her flesh and blood."" The child, Jeremy, shares in her anonymity: ""Anyhow, what a slippery fish is identity; and what is it, besides a slippery fish"" and how totally baffling is la Trout with her ""genius for unreality?"" And would you like her more if you could understand her better? Brushing the cobwebs aside, one is left only with the hooded enigma of her presence, a precarious reward were it not for the calligraphy of one of the enduring, elegant writers of our time.