How does Huck's moral conflict reach a climate in chapter 16

Huck makes this decision spontaneously, when heading to shore to determine what town they are near and with the intention of reporting Jim. On his way to shore, Huck meets two white men searching for runaway slaves. The men ask him who else is on his raft and rather than telling them about Jim, Huck tells them his Pa, mother, and sister are aboard. Huck pretends to be eager for their help and tells them no one else has been willing to pull the raft to shore. At this news, the men become suspicious and finally conclude that Huck's family must have smallpox. Each man then puts a twenty dollar coin on a log and floats it over to Huck to avoid any interaction with him, but only after making him promise not to land anywhere near their town. Huck's ingenious lie fools the men and saves Jim from capture.