Welcome to the Dressing Room, or whatever it is of the interconnected worlds that you've suddenly found yourself in. Wherever you were or whatever you were doing, you are no longer there and no longer doing that. Oh, and you been gifted with a lovely bit of jewelry; a nice shiny handcuff with about two feet of chain on it. Oh and a great big lump of person dangling off it.
We didn't mention the other person? Goodness, there's a person on the other end!
But they're not that important.
What you should be much more concerned with is that you seem to be missing something in exchange for your new companion. How quickly you notice may depend on how much you rely on it.
For example, you might notice being blind a little sooner than you'd notice missing your sense of smell.
The long and the short of it, you are now hand cuffed to someone you may or may not know, on a random world you may or may not be familiar with, and are now missing one of your five senses.
(No cheating and having them lose their sixth.)