Sentence 1: Bob walked down the hall in the building where he worked. 
 Sentence 3: They didn't say anything to each other 
 Sentence 4:  Once they had a large hall in front of then, Bob gave a nod 
 Sentence 5:  On cue, Bob and Joe began a foot race to the end of the hall 
 Option 1: His friend Chelsea came around the corner and walked with Bob. 
 Option 2: His friend Joe came around the corner and walked with Bob.