Alyosha's mentor at the monastery is the spiritual figurehead, Zosima. As his elder, Zosima has complete control over Alyosha. The idea is that through obedience to his elder, Alyosha will be able to gain mastery over himself and attain religious illumination.
Meanwhile, relations between Dmitri and Fyodor have become so bad that Fyodor, half in jest, suggests that they settle it through a meeting with Zosima. Dmitri agrees, and so does his former guardian Pyotr Miusov, who happens to be suing the monastery over a forest. Ivan, who functions as a mediator between Dmitri and Fyodor, is also coming.
Alyosha is filled with foreboding at the prospect of this meeting, and he's particularly concerned that his father is going to cause another scandal.