Dimensional Science has started to unlock the understanding of the fact that the universe is made of layers, and these layers while interacting with each other, are very distinct from each other.
The study and application of technology and human activity
Psychtronics is a field of arcanotechnology that deals with using machines to emulate the mentalist parapsychic realms such as as telepathy, mind control, memory manipulation, and emotional manipulation.
In the years before the advent of arcanotechnology and dimensional fatigue events, teratology was the study of abnormalities and biological deformations. In the wake of the second renaissance, it became the study of exomorphs, extradimensional entities, and most prominently, teratomorphs, more commonly and vulgarly known as kaiju.
The Yugzhee, or "hedgehog-people", guard a great, secret treasure inside their giant burrowed lair. The mysterious Wall of Keys, a 12'x10', foot-thick, cold-iron, "wall", upon which, on iron hooks, hang 100 ornate iron keys of all shapes and sizes. Each key opens some heretofore un-openable barrier, door, or gate, in the particular game world of choice.
The PCs have come upon a great boon, except for the fact that the keys cease to function properly if separated from the iron wall for more than a few minutes. Higher level characters will be able to figure out how to take the wall "with them" via magic. Lower level characters will have to get creative.