The idea here was to mix the D’ni mythology with real world elements *error buzzer*. According to the game’s lore, the entrance to the underground city of D’ni was discovered near a volcano in New Mexico in the 1980s. The archaeologists then approached Cyan and asked them to create a game to educate people about the D’ni. This led to the release and massive success of Myst. In present days, a company called the D’ni Restoration Council, or DRC, has decided to contact adventurers who are familiar with the games to participate in the effort to rebuild D’ni and all the ages connected to it. Allow me to roll my eyes. They even had their own website.
However, the DRC efforts ran into a snag: Yeesha learned about their plans and disapproved of their methods. She thus began contacting the adventurers and telling them that the D’ni civilisation was nowhere near as virtuous as the DRC imagined them to be. They notably enslaved a race of mysterious creatures known as the bahro, who had the possibility of linking at will, without using books. Yeesha’s message was to find a way to free the bahro and allow them to participate in building a new civilisation, not simply reconstructing the old. This created tensions between her and the DRC, but also within the DRC itself, as some people wanted to continue their initial reconstruction project, while others became sceptical. The consequences of these tensions eventually led to the situation as you, the player, find it: the DRC has returned to the surface, and D’ni is abandoned. Yeesha contacts you and tries to win you over to her cause by having you free a bahro (although it’s never quite explained how), and showing you both how far she believes the D’ni had fallen before their civilisation’s collapse and her own powers with the Art. The online version of the game added some further drama to this, as the storyline moved past the events of Myst V and, before the DRC left D’ni for good, involved a civil war among the freed bahro.
Suffice it to say that Uru deserves its subtitle of Ages beyond Myst on more than one level. Whether you think it’s a good move is another question. I certainly don’t.