This is the first Slovak horror film intended for theatrical release.
The building in which the evil itself was imprisoned is located in the village of Bernolákovo, east of Bratislava, the capital of Slovakia.
A poster for the found footage of Paranormal Activity 3 (2011) can be seen in background on the wall in the boys' office.
The film was shot with only one camera.
With a budget of just 100,000 euros, the film was shot in 11 days of December 2011.