The Story of the First Guildmaster
The Story of the First Guildmaster is an apocryphal tale about the creation of the Art, the technology which allowed the D'ni and their predecessors to travel to other worlds, or Ages. It is recounted by Atrus in the short-lived Dark Horse comic book, Myst: The Book of the Black Ships.
As the story begins, D'ni had been suffering from a multi-generational famine. Varsil, the titular "first Guildmaster", was one of the people tasked with perfecting the Art in the hopes of using it to alleviate the famine. With the aid of his apprentice, Atak, Varsil finally succeeded in crafting the first Age, a grain-rich world that he called Dania, after the king's daughter. After showing the Age to Atak, Varsil presented it to the king, Clevis.
Clevis, delighted at the prospect that the famine could finally be brought to an end, offered Varsil whatever he desired as a reward. But when Varsil asked for the hand of Princess Dania in marriage, Clevis was outraged. He refused to allow his daughter to marry someone who was not of royal blood, and had Varsil thrown out of the palace.
Varsil became consumed with rage over the denial of his request. He began to plot an overthrow of the monarchy, intending to create new Ages where he could draw up his own armies for the attack. He attempted to draw Atak into his plans, but his apprentice refused to have any part of it. Although his devotion to his master prevented him from killing Varsil outright for his treason, he also couldn't stand by while Varsil carried out his plans. Atak blinded his master with a crossbow bolt and returned him to D'ni to face the consequences of his actions.
Atak was hailed as a hero for saving D'ni from Varsil's wrath, but he was stricken with guilt over what he had done to his master, even though it had saved his people. Atak ultimately left D'ni, never to return.
When Atrus recounted the tale to himself in his journal, he was searching for a solution to the problem of what to do about his father, Gehn. The lesson he takes from the story is not to let sentiment blind him or prevent him from doing whatever may be necessary for the greater good.
The Story of the First Guildmaster is an apocryphal tale, and contains a number of historical inaccuracies which suggest that it should not be taken as an authoritative or truly historical account of the Art's beginnings. Notably, the Art's origins are far older than even the D'ni. It was originally developed and perfected by the Ronay on their home world of Garternay, an unknown number of centuries before the D'ni split away from them and settled in their cavern on Earth over 9,600 years ago.
Additionally, there is no record of a King Clevis ever ruling D'ni. The DRC's research has uncovered all of the names of the D'ni kings from the first (Ri'neref) to the last (Kerath), and Clevis is not among them. By extension, there is no record of a Princess Dania. And although the D'ni did have a rather rigid class structure, there is no real indication that the D'ni held royal blood to be particularly sacrosanct; the only prohibition seemed to be that if a king ever had a child with an Age-dweller, that heir could not inherit the crown. At multiple times throughout the time of the kings, the crown was passed to a successor from outside of the king's own bloodline. In several cases, it was passed to someone who did not have any sort of royal lineage at all. In that light, it seems unlikely that Varsil's request would have been seen as the sort of outrageous offense that it is depicted to be in the story.