The next morning, Tom/Sid has yet to return. Silas suddenly remembers to give Sally a letter from her sister (Polly, who usually takes care of Tom), but before she can open it, they all spot several figures approaching the farm.
And the figures are: Jim, wearing the stolen dress (!?) and tied up; Tom Sawyer, lying on a mattress; the doctor; and a mob of curious folks.
Everyone wants to hang Jim as an example, but the doctor stops them and tells his story: when he found "Sid" to fix his leg, he couldn't do anything without a second pair of hands.
Sid was clearly getting worse and worse, and finally Jim stepped out of hiding—even though he knew it would mean his own recapture—to save the boy's life.
Everyone's super-grateful, so they decide not to kill Jim.
But they do lock him back up in the shed.
They put Tom to bed and wait for him to wake up and feel chirpy, which he does the next morning.
He then explains everything to his aunt, about how they set Jim free and sent the anonymous notes, etc. He's quite proud of himself, but his aunt is none too pleased.
When Tom hears that Jim has been thrown back in captivity, he flips out. Jim is free, he says, so they ought to let him go.
Everyone essentially says, "What!?'
He explains that Miss Watson died two months ago and, feeling guilty and likely fearing hell, set Jim free in her will.
Everyone is happy, although Silas is probably wondering if he'll get his $40 back, and no one seems too choked up about the fact that Miss Watson is dead.
Adding to the fun times, Aunt Polly shows up, which blows everyone's fake identities.
Huck declares that now he can respect Tom's morality again since he knows he wasn't trying to free someone else's property.
Also, we find out that Tom's been hiding all the letters that Aunt Polly had sent to her sister.