You get a special receipt and then the virgins dance naked around the circle of power. The circle of power summons the Gateway and you all pass to the dimension of Akathamaltur whereas first you cross the lava sea with Tranturian rockships and reach the flying port of Shamal (just by the diamond spires). After the feast of 9 days and 9 nights when everyone is asleep, the aetherial ship will appear, which you will proceed to board and fly through the 8 cloud layers and through the hole of the skydome into the land of the black two horned unicorn, where everything is upside down and made of glassy mirrors.
There you will be tasked with bringing back to the aetherial ship the only creatures not made of glass (the reflections can be annoying) and the correct answer is going to be: Yourselves. (People sometimes get this wrong and they end searching forever until they believe that they are nothing but a reflection). You might also see some black unicorns but that's just a trick.
When you board the aetherial ship again, you go down through the skyhole again but this time you will stop on the 4th cloudlayer, which is actually made of solidified birds, in order to search for the mad elf mathematician who will ask you to bring the 8 side cube to him. Just hand him the receipt and he will give you an egg.
The egg is actually the game, but it needs to be hatched, so back to 2nd cloudlayer if memory serves (the aetherial ship has a GPS but it only speaks in a language where all sounds sound like your mother dieing so most people turn that off), at which point you meet the skeleton of a dragon, which you have to time-reverse in order to make him live again (just use the machine nearby. It has a very intuitive GUI. ), make him hatch the egg, and then finally you will head towards the 8th cloud layer, avoiding the plane of the sex crazed supermodels (lots of people don't return from that one) at which point they usually just sacrifice the noob-est guy in front of the altar of Demonoeconomicon in order to summon the Gateway back to reality.