What did Sid hear tom talking about in his sleep in The Adventures of Tom Sawyer?

In his sleep, Tom is saying over and over again "it's blood, it's blood, that's what it is!" and "Don't torment me so- I'll tell!" What was happening was Tom must have been having nightmares after Injun Joe killed the doctor and in the nightmares he got scared and started talking in his sleep. He wants to tell that Injun Joe really killed the doctor because Muff Potter was getting framed and he had no defense to say he didn't. Tom wanted to make it right because Muff had been good to Tom. He couldn't tell because he and Huck had made a blood oath to say they would never tell.