Who hasn't heard about Myst until now is either retarded or hasn't got a clue about games that wrote history. For the second case there's a quick treatment called Google, but for the first one I'm sure there are plenty of experts out there happy to write you a prescription. Let's just say you know something or maybe you even played, if not Myst or Riven, maybe realMyst, Myst III: Exile or Uru. It's no use telling you why this series will be mentioned by history as one which changed even the way people thought about hardware (due to Myst they began selling PCs with a CD-ROM). There are tones of pages on the subject and lots of dedicated forums. All you need to know is that the story from Myst is one of the most beautiful ever.

     The main characters are, of course, a he and a she. He, Atrus, and she, Catherine. He knows the Art, so he can write Ages. Atrus and Catherine have two sons, Sirrus and Achenar. The two, blinded by the thirst for power, begin to destroy Atrus' Ages. That's why Atrus writes Spire and Heaven, two prison worlds, and lures his sons there, trapping them, hopefully forever. Years pass, and a third child is born, Yeesha. Atrus thinks about teaching her the Art, as she is the only one left and capable to receive all this knowledge. Unfortunately, somewhere, someone has a diabolical plan. This is the story up to Myst IV. There are lots of details that are impossible to cover here (about the D'ni civilization, for example), but in order to get a broader perspective you have to play all the titles or at least search for info in reviews or other sources.
     In the beginning of Myst IV: Revelation you meet with Yeesha who tells you her father wants to speak with you as soon as possible. You don't know who you are and what you should do and that's a common feature to all the Myst titles, but Atrus usually speaks with you like he is talking to a dear friend who would do anything to help him. From Atrus you find out about Catherine's feelings for her sons, Sirrus and Achenar, who, by the way, are not dead, because Atrus has found a way to get his wife and his daughter on the prison Ages. After a series of unfortunate events, Atrus remains trapped inside an Age for a while and Yeesha disappears. What really happened and which is the end of the story is something you won't find out from me. Just play the game.