The missing piece

This is my wife's Christmas jigsaw puzzle. We have looked high and low, taken the sofas apart, all the rest of it, but have come to the conclusion that there was a piece missing when it came out of the bag. You have to send five pieces of it off to the manufacturer who will apparently send a new one. It was a real stinker of a puzzle too, a painting of South Queensferry harbour and the Forth Bridge. Christmas holiday continues.