So when I went to the location of the afore mentioned 4th key, it was not in the door, and it was locked? I have three keys and now I am completely lost as to find the 4th
This does sound like your save is possibly corrupted :|
If you can, hook your Playdate up as a USB drive, and copy the saved data for Etad to a computer (the whole folder including all the "mapstate-x.json" files), zip it up and send it to me (gareth@garethw.net), and I'll get you fixed up.