The most important event in the rising action of Missing May is when Ob does not wake Summer up for school.  Summer thinks that May’s spirit might be watching over them, and Ob thinks he has felt her.  However, Ob gets more and more distant and depressed as May’s death catches up to him.

It was Monday, and Ob should have called me out of bed at five-thirty, but he didn’t, and when I finally woke at 7’o’clock it was too late to set the day straight. (p. 44)

When Ob does not wake May up for school, she realizes that he no longer wants to go on living.  He does not care about himself, or her, anymore.  He is deeply depressed.  He tells Summer he has overslept, but she knows this is not true.  He has never overslept.  She says that God had wanted her to stay home, so she could realize that something was terribly wrong with Ob.