Riven's story continues where Myst and its companion novel, Myst: The Book of Atrus, left off. The player assumes the role of the Stranger, the protagonist of the first game and friend of Atrus (Rand Miller). Atrus knows the ancient art of creating "linking books", specially written books that serve as portals to other worlds, known as "Ages". Atrus needs the Stranger's help to free his wife, Catherine (Sheila Goold; voice by Rengin Altay), who is held hostage on the slowly collapsing Age of Riven. Her captor is Gehn (John Keston), Atrus' manipulative father and self-appointed ruler of Riven. Gehn is himself trapped on Riven, as Atrus and Catherine had previously removed all linking books from the Age; the very last book to be removed, linking to the Age of Myst, was the one they held to escape Riven. In the misbelief that it would be destroyed, they let the book fall into the Star Fissure, a rift leading out of the damaged Age of Riven into a mysterious, spacelike void. Catherine was later tricked into returning to Riven by her sons, whereupon she was taken hostage by Gehn. Eventually, the Stranger discovered the unharmed Myst book, sparking the events of Myst and, some time later, Riven.