Alvin Journeyman continues the story of Alvin Maker as he tries to build the city he saw in his vision. He knows he needs help to do so, and has returned home to try and teach those of his home town how to be Makers as well.

Problems, of course, arise, as it proves incredibly difficult to train them. Worse, Alvin's younger brother, also the seventh (living) son of a seventh son, is quite jealous, as no one seems to realize that he ought to be a Maker too. He wants to be seen as Alvin's equal without all the work.

Alvin gets into trouble when he returns to Hatrack River, and the blacksmith he had been apprenticed to files charges trying to claim the golden plow Alvin made as his journeyman piece. He has a good case, and Alvin is arrested.

The story gets annoying at times, as Alvin refuses to let others suffer, and tries to keep their lies covered up, even though revealing them would help his case. He is accused of fathering a child out of wedlock by a girl from Vigor Church, but refuses to use the testimony that would prove it false, preferring to find another way, even though the testimony comes from a friend willing to prove that she knows how the girl really got pregnant.

Slavers also try to come and claim Arthur, the young black man Alvin rescued in the past. They also want Alvin charged with killing the slave hunter he had killed in a previous book who had been trying to take Arthur back to his rightful owner. However, since Alvin changed Arthur so that he doesn't match the skin and nail samples kept of him, and so the charges are dismissed, and slave hunters rebuked for trying to enslave a free man.

The story also gets into Alvin and Peggy's tumultuous relationship. Peggy is terrified that she will have to endure a loveless marriage, and continues to refuses to see that Alvin has come to love her. 

His brother Calvin, the other seventh son of a seventh son, is getting into mischief in Europe and learning what he feels he needs to know to prove that he's better than Alvin. He works his way into Napoleon's court and learns what he can of Napoleon's skills. In many ways, this is the more interesting part of the story, as Calvin's unashamed ambition makes more sense than Alvin's utter insistence on barely defending himself.