The climax is when Iona tells the policeman that his son has died. The policman actually acknowledges his loss and asks how but when Iona turns his body around to talk to him (as he is guiding the horse down the road) the policeman turns his attention to Iona's poor driving and tells him to hurry up and get to the destination.
The story ends with Iona talking to the horse about his loss. He confides in his horse when no one else will listen. All he wants to do through out the story is talk to someone about how he has lost his son.