During the nights after the trial, Tom is plagued by fear that Injun Joe, whose whereabouts are unknown, will come trying to kill him. Huck is also scared and depressed, because he doesn't know whether Injun Joe has figured out that he too was present in the graveyard that night.
Huck has not followed Tom in maturely fulfilling his moral responsibility to society (perhaps because society has not given Huck much reason to respect it), and Huck continues to prioritize his own interests.
A detective is brought out to St. Petersburg all the way from St. Louis, but even he can't manage to find Injun Joe.
Tom must face the consequences of his serious actions, and can't escape as he might have in one of his imaginary heroic tales.