What superstition does Tom have about the doctor being killed in "Adventures of Tom Sawyer"?
As Tom and Huck are fleeing after witnessing the murder of Dr. Robinson, they are terrified to hear the sound of "a long, lugubrious howl...within ten feet of them". Tom explains that it is a Negro superstition that if a stray dog howls as it is facing a person, that person will die. Tom at first hopes that the howling dog is "Bull Harbison", one of the neighborhood canines, but is horrified when he realizes that it is indeed a stray dog which is making the commotion. The superstition intensifies the terror they feel after having seen Injun Joe kill the doctor, and they fear that the murderer will discover that they were witnesses to the crime and will come after them next. Tom and Huck "reckon (they're) goners", until Tom notices that the dog is not facing them but has its back to them instead. The "strange dog (is) standing within a few feet of where (Muff) Potter (is) lying, and facing Potter, with its nose pointing heavenward" as it howls. Tom concludes that "Muff Potter's a goner...that's what the niggers say, and they know all about these kind of things". This prediction is actually more plausible than it seems, because Injun Joe, taking advantage of Potter's inebriated state, plans to pin the murder on Potter instead of himself (Chapter X).