B.J.'s mother is a real detective, having taken over the agency when Dad died, and when B.J. decides on her own to help Mom with a shoplifting case, it seems that culprits, informers and others who are sort of both keep popping up--at school, in her home, and in the department store where she goes to check out a tip. In an effort to shield or save Sammy, who with his Mom has come to stay with B.J. and hers while his Dad is in prison, B.J. gets herself captured by the man who's been directing the juvenile operation. Sammy turns out innocent--he's just been collecting evidence--and fat Sue Niles from school, who was involved earlier, will get off light for helping B.J. Like Silverthorne's Ghost. . . (p. 661, J-229) from the same publisher, this ends with the three children hogtied and tossed into a truck. . . but there's Mom with a police roadblock at the state border, and hugs all around in a true-to-type cops and rompers finale.