As usual, Davies gets the case at the bottom of the investigative pile. But it leads him to something much bigger: the unsolved murder of a 17-year-old girl. Davies works on the case unofficially with the help of his friend Mod, who is frequently available as he goes from odd job to odder job.

Davies investigates the disappearance of a man whose wife seems curiously unconcerned about his whereabouts. Because the investigation takes them to a dance club that caters to senior citizens, Davies and Mod face the additional challenge of remaining light on their feet.

Dangerous takes on two cases shunned by the rest of the department. In one, a lady is sure t her neighbor has killed his wife. In the other, a demanding female robbery victim seems to become enamored with Davies.

An eccentric old man Davies has befriended in the park is found dead in a canal. After meeting Jemma, the old man's social worker, Davies decides to take on the case, because no one else will and because it might bring him closer to Jemma.