The conflict is mainly between the protagonist, Delia, and her husband, Sykes, who is horribly mean and cruel to her. He is cheating on her and has before and treats her as if she is a servant. He also beats her.
She has taken all that she can handle, but is limited by her race and gender as to what she can do about it. This is why when the snake bites Sykes, she simply watches him die...she can't make herself save him. Anyone could understand why she would have done what she did, really.
At the end,
Sykes, whose head is clearing from gin, hears nothing until he reaches behind the stove to look for a match. But they are all gone, and Sykes hears the rattling right beneath him, so he leaps up on the bed. Delia can hear a horrible scream as Sykes is being attacked, and she becomes ill. While lying down to recover, she hears Sykes moan her name and gets up to walk towards the door. He crawls towards her and realizes that she had been there the whole time.
Because of this, Sykes dies, realizing, though, that Delia had seen him get bitten and that she did nothing about it. Perhaps then Sykes might have realized the many errors of his ways.