LADY ORACLE
by MARGARET ATWOOD
345 pages. Simon & Schuster. $8.95.
Alice in Wonderland is alive and well and living in Margaret Atwood's new novel. She has changed a bit: she operates under the alias Joan Foster, resides in Toronto and writes gothic romances on the sly. But she still has more identities than she knows how to handle, takes pills that make her undergo disconcerting changes of size, and gets into trouble by gazing too long into a looking glass.
Most of the time, Joan Foster is the quietly unremarkable wife of a humorless...