THE BRANDON PAPERS : by Quentin Bell; (Harcourt Brace Jovanovich: $15.95).

”. . . Three men came into the room, my husband, Selmersham and the buttons. Charlies was armed with a whip, Selmersham with some lengths of cord. I perceived that we were about to face circumstances which, although they had been. . . .”

And so ends “The Changeling,” a novel within the first novel, “The Brandon Papers,” by Quentin Bell, nephew and biographer of Virginia Woolf. What has come before is the story of Lady Brandon, who was known first as Mary Porthow but who was, really, Henry Brandon. Yes, it is complicated, but it’s also delightful and far, far more than a story of lifelong cross-dressing. Preparation for his life as Mary Porthow--deceased in peculiar circumstance, but an heiress, hence Henry Brandon’s interest--involves being alert, writes Bell, to “the disaster of the too-visible petticoat, guest left unintroduced, an inattentive servant, an intelligent idea.”

Some of this material is covered in “Lady Alcester’s Memoirs,” yet another story within the story, written by the woman instructing Porthow/Brandon in the art of being a lady in late Victorian England. There is also: mention of aberrant sexuality, attention to social class, a profusion of literary devices, some suspense and quite intricate plotting, and everything is infused with great wit and sophistication.