The early section of "The Birds Fall Down" doesn't exactly ease one's forebodings. . . But don't underestimate Dame Rebecca. The moment old Diakonov has left the house, an oddly intriguing note creeps into his garrulity. . . . I fault the story only for permitting itself too many undelirious figures. . . But ultimately Dame Rebecca comes through like her own best characters. Her follies as a writer only set off her virtues.