How does Tom get home? Why does he go?

Tom and the boys decided to attend their own funerals. They paddled over on a log.

They had paddled over to the Missouri shore on a log, at dusk on Saturday, landing five or six miles below the village; they had slept in the woods at the edge of the town till nearly daylight, and had then crept through back lanes and alleys and finished their sleep in the gallery of the church among a chaos of invalided benches.