Without explanation or warning, a number of mysterious, alien “doors” suddenly appear in every corner of the globe. While many of those that encounter these sentient doors feel the strange urge to interact with them – never to be seen again – others stay behind to face the potential threat of what their true agenda towards mankind is.
In a rush to determine the reason for the arrival of these cosmic anomalies, the government enlists volunteers to brave the journey to enter the doors so that we might learn more about their origin or purpose. But even these brave volunteers are not prepared for what lies beyond the threshold.