A boy named Mike loved his grandpa very much, but one day, his grandpa died suddenly. At the funeral, Mike saw his grandpa was sitting on the bench. He told his mom, but his mom could not see.
When Mike came back home, he opened the door when someone rang the bell. His grandpa was standing outside as a ghost! The ghost grandpa told Mike the reason he came back was that he left one thing behind, however he could not remember what it was. So, they decided to find out the answer together.