Which of the following was not mentioned in the sequence of events in the passage?

The answer is appropriate because the passage does not include any reference to searching for treasure as part of the narrative's events. In the context of the passage, the sequence of events typically revolves around specific actions and occurrences that are explicitly mentioned. In contrast, the other choices package relevant details that align with the story’s focus, such as the ponies vanishing, a discussion about an island that could provide context about the setting or destination, and a cry being heard, which all contribute meaningfully to the buildup or climax of the narrative. This emphasizes the need to look closely at the wording and events provided in the passage to determine which elements are directly presented and which are absent from the storyline.