Gehn is the son of Anna (Ti’ana) and the father of Atrus. He believes that he has the ability to create worlds by writing linking books and eventually becomes trapped on Riven (by Atrus & Katran). He rules Riven with a rod of iron and believes himself to be a God. When Katran becomes stranded on Riven he captures her and holds her prisoner on Prison Island with the intention of making her his wife.
The linking book to Riven was written by Gehn and because his writing is flawed so the age of Riven is flawed also, it is gradually collapsing with the single land mass of Riven rapidly breaking up into five separate islands, the smallest of which, Prison Island, drifts furthest rendering it accessible only via Gehn’s 233rd age.
Gehn was played by John Keston, a British actor who, apart from being an accomplished opera singer, actor, musician and teacher is also an avid marathon runner, at 76 he set a world age record running the Portland marathon in 3 hours, 22 minutes and 59 seconds.
John will be 90 this year (2014) and is still running marathons!