Summary In a small city on the banks of the Mississippi comes a young lawyer from New York, David Wilson, soon nicknamed the pudd'nhead for wanting to kill half a dog not belonging to him Moreover his favorite pastime is to collect the fingerprints of the passers-by. His fame is made ... At the same time, Roxana, a young Metis slave (one-sixteenth of black blood) raised and fed two blondinet boys, his and his master, Percy Driscoll, brother of the county court judge. To avoid the sale of her son in a plantation, she substitutes the two infants. The fake Tom should make a great career ... Twenty years later, two young Italian nobles, twins, arrived in the same town. Tom the impostor plundered, plays and sells his own mother in a plantation. He eventually murdered his uncle and guardian. But Wilson with his fingerprints puts everyone in his place ... And the twins? This is an other story... "The reader knows from the beginning the author of the murder and how the crime will be solved. The circumstances of the denouement, however, were at that time a great novelty, taking fingerprints was not then commonplace for the detection of crimes in the United States. Even a man for whom it was a hobby was treated as a nigaud, a 'pudd'nhead'. (Introduction by Langston Hughes to the novel) The story also describes Missouri's pre-Civil War racism, even vis-a-vis the seemingly white people with a trace of black blood and the acceptance of this state of affairs by everyone, The black population."