Serious modern fiction has only one subject: the difficulty of writing serious modern fiction." So says Fowles' alter-ego here. And, if that idea was an undercurrent in The French Lieutenant's Woman (the time-shift narrative tricks) and Daniel Martin (the writer-as-tortured-hero), Fowles is now offering it in undiluted form: this new novel chiefly consists of existential dialogues between a writer and his Muse--along with some Pirandello-ish gamesplaying and an erotic battle-of-the-sexes. Miles Green wakes up in a hospital bed, apparently afflicted with amnesia; soon a lovely doctor and a sexy nurse are matter-of-factly administering therapeutic sex to the outraged patient. What's going on? Is this a farce Ã la Thomas Berger (with dialogue by Pinter)? Well, not exactly. Because the doctor is suddenly transformed into Erato, Muse of love-poetry and fiction: the hospital scene, you see, was just one of Miles' literary notions. So Miles and his tetchy, pouting Muse then launch into some comic/philosophical discussions, with time-outs for brawling and bedding. The feminist Muse attacks Miles' work; she demands respect ("All I ask is some minimal recognition of my metaphysical status vis-Ã -vis yours"); she recalls her early days with the Nine Muses ("It was worse than being the Rolling Stones"); she makes suggestions about Miles' career; she confesses to having written the Odyssey. Miles responds with lectures on the modern novel. And, throughout, the tussle between writer and Muse is interwoven with the sexual struggle between Man and Woman: teasing, spats, fights, and--after some more transformation games--happy lovemaking. Fowles, of course, executes his "mantissa" (O.E.D., "an addition of comparatively small importance") with vast erudition and lovely prose bits. But the less characteristic comedy is uneven--from sublime to sophomoric. (Erato confuses lung with Erica Jong.) And, however richly executed, this remains an overextended intellectual vaudeville-sketch--alternately fascinating and tedious, with distinctly special, limited appeal.