A slight, uneven, but likably amusing debut for Farrell--who was once an aspiring NY actress, as well as a part-time assistant to a private detective, and who uses both experiences in concocting this mystery-cum-satire. Farrell's alter-ego heroine is out-of-work actress Annie McGrogan, who eagerly grabs any temp assignments she can get from ``Duke'' DeNobili, ex-cop turned big-time p.i.--including the job of baby-sitting soap-opera star Lucinda Merrill, who's been scared by anonymous threats. And so, when Lucinda's kinky, druggie husband is murdered, Annie--who can swear she was watching over Lucinda on the night in question--becomes the key to the TV star's alibi. But what about the eyewitness who saw Lucinda at the murder site? It's up to Annie to puzzle out this contradiction and clear Lucinda's name. The plotting is obvious and paper-thin. But, though Farrell's comic touch is occasionally labored and crude, her sendups of show- biz--the crass soap-opera scene, the pretentious off-off-Broadway world (where Annie auditions)--hit the target as often as not. And Annie herself--helping her gay-actor pals, fending off a worthless (but sexy) ex-boyfriend, and pluckily mingling with assorted lowlifes--is an acerbic yet warmly agreeable narrator.