Atrus (played by Rand Miller in all of the games) was trapped on the island of K’veer in the ancient city of D’ni by his father Gehn, his only escape was a linking book to Riven, where he met his future wife Katran (Catherine).

Together they trapped Gehn on Riven and with the help of Anna (Ti’ana) Katran wrote the link to Myst Island where they escaped to - Atrus managed to destroy every other linking book on Riven and joined Katran and Ti’ana on Myst Island dropping the Myst linking book into the Star Fissure as he did so.

The Stranger finds the Myst linking book and so the story of Myst begins. Katran was later tricked into returning to Riven by her sons Sirrus & Achenar and was thus stranded, Atrus employed the help of the stranger (once again) to rescue her while he did his best to stabilise the age of Riven, hence the story of Riven begins.