Tall and blond, Geoffrey is the brother of Sukey, but unlike her, he seems nice. This is a good thing, because when Blade's sister Shona appears in her role as official Bard to their group, the two of them -- Geoffrey and Shona -- each fall in love at first sight.
Blade is not happy about this, because in addition being from offworld, Geoffrey is marked down on the list of tour members as an Expendable -- in other words, the Wizard Guide is supposed to make sure he is killed during the tour (by pirates or elves, depending on how things worked out). This is another of the many ways Mr. Chesney makes money off the tours, by making relatives or business rivals pay a lot of money to get rid of people they would find it convenient to be without.
As the tour progresses, Geoffrrey proves to be a charismatic leader -- someone who can persuade nearly anyone to do nearly anything, just by telling them to in a charismatic way.
During the final massive resolution events, it becomes clear just exactly what Geoffrey's secret is, and we find out if he and Shona are fated to break up or stay together. An interesting character and a good plot point for the story.