At the local market, Santiago trades his old book for a new one, and just as he is becoming absorbed in it, an old man asks him what he is reading. When Santiago shows it to him, the old man says that the book is important but irritating. The old man goes on to say that the book describes its characters' inability to choose their own Personal Legend. He also says that everyone in the book believes the world's greatest lie: that as people get older, they lose control of their futures and their lives are directed only by fate.
When Santiago asks where he's from, the old man replies that he's from many places but was born in a place called Salem — of which he is king. His name, he says, is Melchizedek. He offers to help Santiago find the hidden treasure in exchange for one-tenth of his sheep. Then Melchizedek writes in the sand the name of Santiago's hometown, his parents' names, and the name of the merchant's daughter. While he is writing, Melchizedek's cape falls open, revealing a blinding light.
Melchizedek explains that Santiago has discovered his Personal Legend, which he defines as "what you have always wanted to accomplish." According to Melchizedek, every young person knows what his or her Personal Legend is. It is only as they get older that a "mysterious force" convinces people that Personal Legends are impossible to achieve. This mysterious force isn't exactly negative, since it prepares a person's spirit and will so that he or she can understand "the one great truth on this planet." This truth is that ". . . when you really want something, it's because that desire originated in the soul of the universe." Fulfilling that desire, which means fulfilling your Personal Legend, is everyone's purpose, Melchizedek explains. The Soul of the World is fed by people's happiness, he goes on. In fact, a person's only real responsibility is to realize his or her destiny. "And when you want something," Melchizedek concludes, "all the universe conspires in helping you to achieve it."
Melchizedek tells Santiago that he visited him just when Santiago was about to abandon his Personal Legend — searching for and finding a hidden treasure. Melchizedek always visits just when a person is about to abandon his Personal Legend. But Melchizedek, the king of Salem, doesn't always appear as a person. Sometimes, when people are about to abandon their goals and dreams, he appears to them as the solution to a problem or a good idea, or he just makes things easier to achieve.
Melchizedek and Santiago arrange to meet at the same time the next day. Santiago will give Melchizedek one-tenth of his flock, and Melchizedek will tell Santiago how to find the hidden treasure. After his exchange with Melchizedek, however, Santiago walks to a ticket counter where he considers buying a ticket to Africa. Ultimately he decides against it.
Santiago and Melchizedek meet again, and Santiago expresses his surprise that the same friend who was housing his sheep has agreed to buy all the sheep that Melchizedek isn't purchasing. Melchizedek tells Santiago that this is called the principle of favorability, otherwise known as beginner's luck. The king of Salem explains that a force wants us to realize our Personal Legends, and beginner's luck gives us a hint of what success might feel like.
Melchizedek tells Santiago that the treasure is in Egypt, near the pyramids, and that he can find it by following the omens. Melchizedek opens his cape and removes one black stone and one white stone from the center of his breastplate, which he says are called Urim and Thummim. The black stone stands for "yes" and the white stone for "no," he says, advising Santiago to rely on the stones when he can't read the omens. Melchizedek gives Santiago two further pieces of advice: Don't forget the language of omens, and don't forget to follow your Personal Legend through to its conclusion. When he bids Santiago farewell, Melchizedek recalls giving advice to Abraham and apologizes to God for his vanity.
In times past, literacy was unusual among people who weren't members of the aristocracy or the clergy. Santiago himself is literate only because he studied for the priesthood. Therefore, it is significant that the old man can read and has already read Santiago's book; this means that Melchizedek is actually a very important person of high status.
This episode is central not only to Part One of The Alchemist, but to the novel as a whole, introducing as it does the concepts of the Personal Legend, the world's greatest lie, the mysterious force, the Soul of the World, the principle of favorability (beginner's luck), and following the omens. These concepts will recur throughout the novel, motivating Santiago's actions and explaining to him many of the apparently inexplicable things he experiences.
The name Melchizedek, Hebrew for "righteous is my king," comes from the Old Testament, in which a character by that name is identified as the king of Salem (another name for Jerusalem) and a priest of God in the time of Abraham. Because the Melchizedek of The Alchemist recalls charging Abraham his one-tenth fee, we can assume that he is the same Melchizedek.
Other than Santiago himself, Melchizedek the king of Salem is the novel's most important character. And he is certainly a contradictory figure, urging self-reliance and discouraging passivity at the same time that he intercedes in the service of those, like Santiago, in danger of not being self-reliant enough.