Bob went down the hallway and opened the back door of the storage room.  "No one's here." he said.  "Go in the front."

She opened the door and looked around.  The place was empty.  "But the back door is locked!" she said, and pointed to the door that she had just locked.

Bob looked and didn't notice anything out of place.  He had been a private investigator for years and nothing ever surprised him.  She closed the door and walked to the front door.  "I'll get the phone," Bob said.

She walked into the kitchen.  It was empty.  "Where are everyone?" she asked.  There were several people in the house.  She was sure she saw someone in the living room watching television.

She walked to the living room.  Someone was watching television but it was in black and white.  The set looked old.

He stood and asked her why she was there.  "Someone was watching the television and it looked old," she said.

"Your friend, the one you brought in," he said.

She looked at him strangely and told him that the friend was gone and the television had always been in color.  Then the television switched to color.  He knew