A machine is invented that enables "trans-dimensional" travel. That’s the popular name — really, it transferred the contents of a spherical volume on a continuously variable change of fundamental constants. These are not the constants we know — they are much more "fundamental". There is always the possibility that you will change things in a way that is outside the range in which the machine will work, or that your mind or body will continue to work. Also, there is the possibility that you won’t be able to return.

Intrepid explorers decide to try, but decide to stop when they return to discover that they (and everyone else) have pig snouts.

TBC…​