In the mainquest of Skyrim you found the Elder Scroll of time with the Elder Scroll in you inventory a quest starts, you must go to a specific place somewhere in Skyrim, where you open a gate and travel to Cyrodiil. In Cyrodiil a elite imperial soldier attacks you. You kill him, suddenly other imperial soldiers come and catch you and knock you out. When you awake you are in a cell. You have to rest in the bed. When you awake next a guard is in your cell and says a mighty person wants to speak with you. He brings you to the Emperor, who tells you that the soldier you killed was a agent, which was on his why to Morrowind, he says you have to go now and are now an agent of the Empire. The next scene is the intro from Morrowind when you come with the ship to Morrowind.
(I don't say you should make whole Cyrodiil, only a little area where this scenes are taking place.)
(Somewhere in Morrowind you can find a gate back to Skyrim)
What do you think about that?