Sentence 1: Frank walked to the arcade near his house. 
 Sentence 3: His mother noticed Frank was missing 
 Sentence 4:  She worried when she couldn't find him 
 Sentence 5:  When Frank walked back into the house, she was relieve 
 Option 1: His mother worked at the arcade and he saw her there. 
 Option 2: He had forgotten to tell his mother where he was going.