Margaret just says no to a vicious Manhattan drug lord.

The kettle is still on in Sarah Feiner's tiny apartment on the West Side of New York, but Sarah herself is dead, with a thousand dollars in her shoe and no sign of forced entry. The police suspect that, astonishingly, this elderly woman had been working as a money runner for a cocaine dealer - a theory hard to prove until unflappable senior citizen Margaret Binton persuades the police to let her take up where Sarah left off, working as an undercover agent in the guise of a bag lady.

Even though she is watched over by two alert guardian angels, Sgts. Schaeffer and Jacobson, Margaret knows that if she messes up she will, like Sarah, be put into final retirement. And her new job soon requires much more of her than foraging in garbage cans and toting little packages around the neighbourhood.

So, without telling the police, she devises her own brilliant trap to catch the killer. Its only fault is that Margaret herself must be the bait.