The Invisible Fall

15:17, Platform 7 on the Seventh Ring Road. The four-storey public surveillance display wall across the way had cycled round to camera three — No. 12 Residential Tower on the Seventh Ring Road.

In the picture a person was falling from the twelfth floor. Halfway down, the one watching blinked. When his eyes opened again the person was gone and the picture went on playing. On the platform nobody looked up, nobody spoke, nobody stepped outside the lines. The bus pulled in with a margin of 0.05 seconds, and the doors opened and closed.

The student access channel can pull the past 6 hours of low-resolution public footage. That stretch was replayed three times and there was nothing. Switching to the backup channel on the school database, applying for live authorization with a student number, waiting 0.8 seconds, approved, replayed, the same.

What was wrong lay elsewhere. In the 3 seconds from 15:17:08 to 15:17:11 the picture was too smooth: not once did the wind move a leaf on the street trees, the brightness of the icons on the roadside signals did not pulse, and even the driverless car that in the neighbouring time slots should have crossed the intersection at the lower right of the frame at 15:17:09 did not appear. For a full 3 seconds nothing on that street moved at all.

The building is still there. Below it there is no crowd, no cordon, no trace of cleaning; the vitrified reflective coating on the paving tile is as clean as every tile beside it, and the brightness of its reflection matches the reading from the Skylink ambient light sensor to the second decimal place. The windows on the twelfth floor are all shut, the curtains the standard grey-white of New Capital residential towers, the sill never struck. Walking over that tile, a lifted foot changes direction of its own accord, swings out into a half arc and comes down on the one beside it.

The glass door of the convenience store across the street faces that building at an angle. In the reflection on the door glass, the grey-white of that whole row of twelfth-floor windows is a shade deeper than the real thing. Look back at the real thing and you cannot tell the difference.