Tom and Huck go into the woods to get fox-fire to have a light to dig by. Fox-fire is a softer light than a torch. A torch would cast too much light and betray their positions.
Tom is dissatisfied that the plan is still too easy. There is no watchman and no dog. Jim is chained up but can be easily freed. There is no honor in freeing him when there are no dangers to overcome.
Tom wants a saw. They could lift the bed to free Jim’s chain, but that is too easy. He wants to saw the leg off the bed. Huck dissuades Tom from sawing Jim’s legs off.
Tom also wants to send Jim a rope ladder in a pie. Huck doesn’t see the need for it, but Tom says it has to be used. It is simply how prison escapes are done. Huck points out they’ll get into trouble with Aunt Sally for tearing up her sheet.
Tom wants to steal a shirt so Jim can keep a diary. Huck points out that Jim can’t write. Nobody will be able to read what he would scrawl, so there is no point. Tom, though, is obsessed by how things are done in adventure books. Prisoners always keep a diary.
Tom justifies stealing when it is on the behalf of prisoners, so long as the items are needed. When Huck steals a watermelon to eat for himself, Tom gets upset and makes Huck pay for it.
Tom doesn’t want to use picks or shovels to dig. It is too easy. They need to use case knives. It may take years to get Jim out. Huck says Jim doesn’t have years.