Throughout Jim's escape from the Phelps's house, Mark Twain uses Tom Sawyer as a foil for Huck Finn. Tom is impetuous and only concerned with making every moment of Jim's escape exciting. He is not concerned with Jim's freedom but rather with having a good time by helping him run away. Huck on the other hand has very different motives. Huck feels genuine compassion for his friend Jim and wants to see him become free.
When Huck first introduces to Tom that he wants to free Jim, Huck is very surprised by Tom's reaction. Tom is delighted to help him and this shocks Huck. "Well I let go all holts then, like I was shot only I couldn't believe it. Tom Sawyer a Nigger-Stealer!" responded Huck. Huck cannot understand why "a boy that was respectable and well brung up had a character to lose folks at home that had characters bright and not leather-headed and knowing and not ignorant; and not mean but kind to stoop to this business and make himself a shame, and his family a shame." Huck does not realize that Tom will do anything for entertainment, even gamble with the freedom of a black slave. This scene exemplifies the differences between Tom and Huck. Huck realizes that it is morally right to help Jim despite the outward influences that tell him otherwise. Tom on the other hand holds no moral regard for Jim or any other slave for that matter.
Huck and Tom's plans for freeing Jim also differ in accordance to their personalities. Huck's plan is relatively simple and straightforward. He plans to steal the key to the shed where Jim is being held captive and return to their canoe where they can hide out. This plan however is not acceptable to Tom. It lacks the risk and danger that he has read about in his adventure stories. Tom refers to Huck's plan as "mild as goose-milk." Tom says, "it wouldn't make no more talk than breaking into a soap factory." He decides on a plan that is a lot more intricate and convoluted.