As Francesca, Baer’s mordantly funny first novel, swells the burgeoning ranks of ”bad girl” lit: It seems like every chick recently slipped between book covers boasts of being promiscuous, addicted, alcoholic, or at the very least, a stripper in her undergraduate years. Elaine Botsch is on the corporate fast track, courtesy of career-advancement techniques they most definitely don’t teach at Harvard Business School. She arrives at work each morning energized by nights of anonymous, degrading cybersex with ”Inez,” an Internet dominatrix. But one night Elaine logs on without her online nickname, ”Francesca,” a slip that spoils her nightly trysts and leads her to suspect that her mistress is, in fact, someone at work. Baer stages a snappy, paranoid mystery out of Elaine’s frantic attempts to find Inez and restore the nighttime identity that sustains her professional one.