Dickon is down by the waterfront near his grandfather's warehouse when he sees a young fishmonger being chased by three older and bigger mercer apprentices. Coming to the aid of the boy, Dickon fights with the three bullies and drives them away.

For his part, Dickon looks forward to being apprenticed to the Grocers' Company. Grocer apprentices and mercer apprentices are sworn foes. When he finds that he has been apprenticed instead to his godfather, Richard Whittington, master mercer and three-time Mayor of London, Dickon momentarily forgets that this is a great honor. He is distraught both that he will not be a grocer like his brother and grandfather and that he will be in the same guild as the three ruffians who have just become his enemies!

But Dickon's fears of meeting them again are overshadowed by far greater fears when he finds himself unwittingly involved with a dangerous secret organization that is plotting against the king. His attempts to protect the innocent only serve to get him into deeper trouble.

In this exciting adventure story, Cynthia Harnett has created a vivid picture of life in London in 1415, a turbulent time in which Henry V was battling unrest at home and fighting abroad to secure the French throne

From the dust jacket of the 1984 Lerner Publications Company reprint