At the heart of this whimsical novel is the theme of friendship.  The antics of the friends Tom Sawyer and Huck Finn are known to many Americans who have not even read this novel.  Together Tom and Huck create an exciting, imaginative world.  Many readers long remember the scene in which Tom tricks his friends into whitewashing the picket fence, Injun Joe leaping through the window of the courhouse after Tom names him as Dr. Robinson's murderer, and the cave scene in which Tom and Becky are lost have become part of American folklore.  Finally, when the children return to attend their own funerals and all the relatives are elated to find the children, Tom remarks that "it ain't fair" that Huck stands alone with no one to welcome him back.  A true friend, Tom tells Aunt Polly that someone must "be glad to see Huck."