The climax of this excellent tale to my mind comes when Keawe feels he has finally sold on the bottle imp only to discover that his wife has actually bought it off him and will face eternal damnation in his stead because of the love she has for him. Note Keawe's dilemma ashe realises this shocking fact:
Now, the money that Keawe had taken was only some of that store of centime pieces they had laid in at their arrival. It was very sure he had no mind to be drinking. His wife had given her soul for him, now he must give his for hers; no other thought was in the world with him.
Thus this is the climax of the story precisely because it is the most tense moment. Keawe must find somebody to buy the bottle imp from his wife so that he in turn can buy it and therefore free his wife from eternal damnation burning in the flames of hell. But will he be able to do it with so much riding on this act and with the price of the bottle now necessarily being so low? The rest of the story reveals his success.