Right next to a stripmall with a grocery store, liquor store, 3 fast food joints, and a classy Mexican restaurant stood a convenience store. As the large franchises often do, they had constructed a standalone building so it could have the exact same layout as every other convenience store in the chain. But it had not done well, and after just a year the location had gone out of business.
The empty shell of a building lay unoccupied for only a year before a competing franchise built their own standalone building at the other end of the strip mall. They had slightly more luck and have stayed in business due to the opening of a new college campus just down the road. Nearby apartments were renovated, and now the strip mall is doing well. Despite the success in the area, the building has remained empty for nearly 5 years. About 6 months ago, a local startup rented the building and has opened their own convenience store - Margo's.
In the last 6 months, some unusual things have happened. A man drowned in a pool and while he was being examined by a coroner woke up and explained he had fallen off his raft while taking a nap. Many members of the college's cheerleading squad look identical, not to mention having absurd measurements that refuse to obey the laws of physics. A thief was found suspended in the air beneath a nearby bridge unable to move... with nothing keeping him in place; one tap by a police officer's baton dropped the thief painfully to the ground.
And that doesn't even touch on the number of people, mostly college students, with unusual or extra body parts. At first no-one "noticed" - they saw and interacted with the changed people as normal and even acknowledged and accounted for the changes, but didn't seem to be particularly aware that the changes were actually unusual. Something about the changed people seems to prevent others from "noticing" and sounding the story. The media still hasn't noticed.
One day, a person or group of persons entered the store for the first time...