Character A works at an antique store that’s going out of business. When cleaning out a section of the store, they find a zip-lock bag containing a charm, a length of twine, and a frayed business card with an unknown language printed on it. Curious, Character A takes the necklace to twins Characters B and C, who are both aspiring antique dealers, to find out what the necklace is. As they’re inspecting the charm, it breaks/cracks/opens/begins to glow and the three characters find themselves in a different reality that is like theirs, but indescribably off in a way that they can’t quite put a finger on.
It’s up to the author to figure out what is going on and how to get the three characters back to their own dimension, if at all.