Sentence 1: Mitch went to the art gallery to look at a friend's artwork. 
 Sentence 3: He waited for three hours and his friend never showed up 
 Sentence 4:  Mitch decided to call his friend and find out what happened 
 Sentence 5:  Mitch's friend was at another art gallery and they both laughed 
 Given Sentence 2: When he arrived he noticed the friend wasn't there.