Assoc. Barkin Bayram is a physicist at his forties. When he entered the police building for license and passport operations he was killed without leaving a trace in front of everyone . Behzat thinks the killer is still in the building. Entrance and exit of the building closed down, and starts searching for the killer. It will not be easy to find the killer even though they are in the same building. Barkin's murder will become more complex than they expected.