Doodled this up the other day, both to get an idea on paper, and to use as simply some more sphinx practice.
The idea was fairly simple to start. The ring tf concept, except with two rings, at different locations, and the size difference in the ring causes a size different in the subject that passes through them.
From there it kinda evolved into an experiment gone wrong. The size different wasn't intended, but during this particular test, they got hit by a sudden surge of power which overloaded the destination ring and caused the link to jump to a larger target capable of handling the energy. In this case, the 'ring' of a nearby ferris wheel.