Gilbert Markham, as of yet unnamed, is writing a letter to his brother-in-law, Jack Halford, in which he promises to atone for having offended Halford the last time they met. At that meeting, Jack treated Gilbert to stories about his youth. Gilbert, not in a sharing mood, did not reciprocate. Now this friendship of long-standing is strained, and Gilbert hopes to soothe any hurt feelings with this letter about an important time in his life. Gilbert warns Jack this will be a long tale and a thorough one, and he is using not just his memory but his journal from that time to paint a full picture.
Gilbert’s first letter to Jack sets up the novel’s epistolary structure—Gilbert has a specific audience in mind, though the general reader is also privy to this correspondence. It also prepares the reader for a story that, at least to Gilbert, proved life-changing. The fact that readers aren’t treated to tales of Jack’s youthful indiscretions suggests that Jack will be only a minor character, and that does turn out to be the case. He mostly just acts as a stand-in for the reader.