Sentence 1: Amy and Kim were going over their friend Lynn's house. 
 Sentence 3: Her mother was in the basement, and hadn't heard her 
 Sentence 4:  An hour later her mother was worried when she couldn't find her 
 Sentence 5:  An hour later Amy called and her mother finally calmed down 
 Given Sentence 2: They didn't know any of the kids on the block.