What do Tom and Huck witness in the graveyard? What is their initial reaction to what they see?

The two boys flee from the graveyard in horror at the scene they had witnessed: the murder of Dr. Robinson by Injun Joe. Out of breath and always looking over their shoulder, Tom and Huck manage to run all the way to the deserted tannery where they find shelter.

Once they gain their breath, the boys rationalize as to what they should do. They have the choice to tell people or remain silent out of fear that Injun will come after them.Not knowing that Injun Joe is attempting to frame Muff Potter for the murder, the boys decide to not tell a soul about what they had seen for fear that Injun Joe would seek revenge upon them as well. The murder that Tom and Huck witness breaks the sense of innocence and wholesomeness that has, until then, enveloped the small-town life of St. Petersburg.