Board Thread:Questions and Answers/@comment-87.254.93.105-20130127000057/@comment-173.71.27.18-20130208103254

Then you'd be stuck in the Nether.

If you're going to use MystCraft, always carry a Linking Book that you created in the Overworld, or else you will be stuck forever. There is a teleport cheat, however, and you can always move yourself back to the Overworld using MCEdit.

The teleport cheat is "/tpx [dimension]" where [dimension] is the number of the dimension you want to teleport to. The Overworld is dimension 0, the Nether is -1, and The End is 1.