first thing that happens is Eteocles ans his brother Polyneices get in a fight for who gets to be king since there father died. in the process they both die. so there uncle becomes king. Creon didn't Polyneices so he said if anyone buries him shall die.
In scene 2 they found Antigone reburying her brother after they removed the dirt. she took the blame. Ismene try to take the blame as well but Antigone wouldn't let her.
Haemon comes to Creon saying he shouldn't kill Antoine to show the people how nice and forgiving he is. Creon doesn't care he wont have a woman be able to break the law and there be no punishment. So he puts her in a cave with food and water so hes not fully responsible for her death.