Sentence 1: Ally and Karen were putting together a puzzle. 
 Sentence 3: They looked all over the house, but could not find the piece 
 Sentence 4:  Then, they saw a tail sticking out from under the couch 
 Sentence 5:  The cat had taken the piece! 
 Option 1: Ally's dog picked up a piece and ate it. 
 Option 2: After a little while, they realized a piece was missing.