This first part of the novel introduces us to most of the main characters, one of these being Professor Otto Lidenbrock. He is the driving force behind the expedition to Iceland to find the volcanic tunnel to the earth's center. Lidenbrock is portrayed as being a brilliant scientist and researcher but also an extraordinarily unpleasant person. Really, he's almost sociopathic in his complete disregard for the feelings, comfort, or even safety of those around him. Case in point: his denial of food to his nephew and housekeeper- and himself- until the runic code is cracked.
The story is narrated by Lidenbrock's nephew/assistant Axel for whom we would expect to feel sympathy, considering how badly he's treated by his uncle. The fact is though, he's such a whiny stick-in-the-mud that it's difficult to like him either. The professor may be too driven and ambitious but Axel seems to have little to no motivation or enthusiasm. He's intelligent enough- he is actually the one who figures out the key to the code- and one can hardly blame him for not wanting to travel to Iceland and hop into a volcano. But all Axel seems to do is inwardly complain; he never stands up to his uncle, whether it's about the trip, his relationship with Grauben, or even- what the heck- being denied food. Even when he brings himself to voice some concerns about the science- or sanity- of descending into the depths of a possibly active volcano, Axel knuckles under immediately when the professor impatiently brushes aside his concerns. He spends a good deal of the book being reluctantly dragged along in his uncle's wake, gloomily predicting their demise at regular intervals, like some sort of Cassandra/Eeyore.