A man walks into a bar with a duck and a biscuit box.

He sets the duck on top of the biscuit box on the bar and the duck begins dancing. The barman finds this rather interesting as do the rest of the punters in the pub. They all come round the duck and watch it for ages, and while doing so, buy more and more drink. By the end of the night the bar is full of people watching this amazing duck, still dancing and giving the odd quack now and again. The barman realizes that he hasn't had business this good in a long time. It is so good that he offers to buy the duck from the man to which the man agrees to sell for 500 pounds. The barman thinks it is a bit expensive but agrees to buy it anyhow. On selling the duck, the man goes home leaving a crowded pub watching his dancing duck. At the end of the night the barman is locking up and the duck is still dancing. The barman thinks oh well time for bed the duck will stop dancing when he wants and the barman goes to bed.

In the morning the barman comes down to open up to see the duck still dancing away on the biscuit tin. The barman thinks to himself, he must really like dancing I'll leave him be. People flock far and wide to look at this dancing duck and with that buying drinks. Throughout the day the barman has taken more money then he normally takes in a whole month. The barman is just locking up at the end of the night and the duck is still dancing away. The barman is concerned that his 'investment' might wear himself out as he's been dancing for the past 24 hours.

Later that night, the man gets a telephone call; it is the barman and he exclaims that the duck is a great success and that he has never taking so much money in the last 24 hours, but he says - "There is one thing... How do you get the duck to stop dancing?" to which the man replies -- "Oh simple - just take the lid of the biscuit box and blow out the candle."