Sentence 1: Barry couldn't figure out where his one cat was. 
 Sentence 3: He thought he heard noises from the ducts but he didn't see anything 
 Sentence 4:  He put the cover back on and started to walk away 
 Sentence 5:  He then heard more noises and realized that the cat was in there 
 Given Sentence 2: They had just painted their living room and a vent cover was off.