It appears you're asking for a description of a fictional book, "Just Duffy" by Robin Jenkins, as a vehicle. This is a misunderstanding. "Just Duffy" is not a vehicle, it's a novel.

However, if you'd like me to write a two-paragraph introduction to the novel in French, let me know and I'll be happy to help. I can describe the plot, themes, and author's style, as well as the novel's connection to "Confession of a Justified Sinner."

Please clarify your request so I can provide you with the information you need.