Some go, and some come, ""in the castle of cats,"" four-month-old Miou learns from oldest cat Oshiva--and that, plus the reasurance that she won't have to go till she's ready, is the old, old wisdom and the ubiquitous picture-book theme that are fitted together and embellished upon here. . . for one of those ethereal, would-be-haunting stories. Miou watches the progress of two departing cats through old Oshiva's magic telescope; plays ""Pounce Ball"" with two new ""calico kittens"" in the castle garden; dreams ""she was running alone in a frightening world""; and gets that comforting reassurance, from Oshiva--""For now, sleep, sleep so close to me,/ in the moon's pale silver sea,/ close to me, so close to me. . . ."" If the writing were more genuinely poetic, this might have somewhat more of a chance to reach the heights it aspires to; the pictures, though very much a la mode (a la super-real, turn-of-the-century mode), do have a certain heightened intensity that compels attention. But all the elaboration--the whole ""castle of the cats"" folderol--is really extraneous.