All mysterious rings found in mysterious and out-of-the-way places are BAD NEWS, that’s all there is to it. Purists please note: this is going to be a ridiculous combination of The Hobbit and LOTR because I have ideas for bits from all over the books, so just prepare yourselves now for a monstrous Bilbo/Frodo amalgam.
Just..if you put the ring on your finger and you disappear, don’t forget to take it off again so we can find you.