In Chapter 20 of The Adventures of Huckleberry Finn, Huck and Jim are looking for Cairo, Missouri where the Ohio River connects with the Mississippi River. When they find Cairo, they can catch a steamboat up the Ohio River into free, non-slave states. Unfortunately, Huck is beginning to feel guilty about harboring a runaway slave on his raft. He decides to go ashore and find out where they are on the river. He also makes the decision to turn in Jim because Huck feels like he is breaking the law (The Fugitive Slave Act).
On shore he meets two slave hunters who start questioning him about who is on the raft. Huck tells them that it is his Pa, Ma, and sister. The slave hunters still want to check out the raft, so Huck gushes about how they are the only ones who have wanted to help them and that no one will come close to the raft. The slave hunters become suspicious and automatically assume that Pa and the others on the raft have small pox. Since small pox is so contagious, they give Huck some money and send him on his way.
The slave hunters represent the hypocrisy of people who won’t help others but instead just give money to ease their own conscience. For Huck to protect Jim shows his growing awareness of racist attitudes in society and the friendship that he is forming with Jim.