Final answer:
At the end of The Chronicles of Narnia, Peter and Susan reveal that they are too old to return to Narnia, marking a significant thematic moment of growth and change.
Step-by-step explanation:
Peter and Susan reveal sad news at the end of The Chronicles of Narnia. They disclose that they are too old to return to Narnia. This moment signifies a turning point in the narrative, emphasizing themes of growth and the bittersweet nature of aging. The invitation to Narnia is akin to a call to adventure in youth, but Peter and Susan must now accept the responsibilities and changes that come with growing up, marking the end of their direct involvement in the Narnian tales.