Sentence 1: John was doing his morning jog by the lake when he saw a stray dog. 
 Sentence 3: He brought it home and put posters around his neighborhood 
 Sentence 4:  At night, the owner of the dog called to come and pick the dog 
 Sentence 5:  When the dog had left, John felt good about himself for helping 
 Given Sentence 2: He approached it and saw it had no collar.