The categories are geometric, temporal, and material. Geometric paradoxes involve space behaving consistently but impossibly. Temporal paradoxes involve time. Material paradoxes involve matter occupying two states simultaneously. Oris has certified two geometric and one material in twelve years. The material was the easiest to document. The geometric ones require six visits and a full surveying protocol.
He drives four hours north to a coastal town. The report came through the usual channel: a neighbor had noticed something about the house next door that she could not account for, had filed with the Bureau, and the Bureau had routed it to Oris, who covers this region. The neighbor's notes are specific. Oris has learned to value specificity. Vague reports are almost always construction or confusion. Specific ones are usually one of those two things also, but occasionally they are something else.
The woman who lives in the house is named Veld. She is in her sixties. She has been in the house for eighteen years and does not try to explain it to him. She makes tea. She sits across from him at the kitchen table. When he asks if he can walk through the house, she says of course, and does not follow him. This is also a good sign. People with constructed paradoxes always follow.
The front door opens to the north hallway. The back door opens to the north hallway. He checks this three times and then a fourth time, slowly. The hallway is in one location. Both doors are where the floor plan says they are. He checks the compass. He checks it again. The hallway is north. Both doors are north and south respectively. He sits on the floor of the hallway for a while.
The stairs: eleven up, eleven down, four-inch descent. He has never encountered this particular configuration. His second certified paradox involved a staircase that added a step on Tuesdays. This is different. This one is simply wrong in the way that cannot be constructed, because constructing it would require moving the floor, which would require a building permit, and he checked the permit records in advance.
He thinks about the third one. The one he certified and then had to de-certify six months later when a structural engineer showed how it had been done. He had been so certain. The certainty itself should have been a warning. He does not feel certain now. He feels accurate, which is different.
He sits in his car outside the house for twenty minutes. The assessment form is on the dashboard. He fills in the geometric data. He fills in the survey protocol results. He checks the box that says Category 1: Geometric. He checks the box that says: Genuine.
He drives away. In the rearview mirror, the house looks like a house. It looks completely ordinary. He has learned that this is not evidence either way.