Emil and his family travel to the town of Vimmerby for the day of the fair. Emil falls in love with the horse Lucas and wants his father to buy the animal for work on the farm. However, the seller is asking to high a price and eventually the horse is sold to a wealthy horse dealer. Later in the day, Emil watches the farrier trying to put shoes on the horse without success: the horse will not hold still and let him do his job, but jumps about wildly. The new owner is disgusted with this wild animal he bought for so much money, and in his anger shouts that he'll give the horse to anybody who can hold him still long enough to put on four shoes. Emil, having realized that the horse is not wild but merely rather ticklish, manages to calm him and hold up his feet. When the horse is shod, the owner is no longer willing to give him away, and thinks he can pay Emil with a little tip. Emil and the crowd of bystanders protest, and in the end the boy is given the beautiful young horse. More excitement is caused when Emil teams up with a local boy of similar age and sends up the firework set up for a display that evening. As luck wants it, there has also been a prophesy that a comet will hit the world that very day, so the townspeople are fully sure this has happened and the end of the world is near when the fireworks go off.