The critically acclaimed second season of Silo ended on one heck of a cliffhanger, with at least one major character’s fate unclear. The streamer just released the first teaser for S3, in which events from the first two seasons rewind to give us the briefest glimpse of the lushly green, seemingly idyllic early days of the silo community, centuries before.

As previously reported, Silo is based on the trilogy by novelist Hugh Howey. It’s set in a self-sustaining underground city inhabited by a community whose recorded history only goes back 140 years. Outside is a toxic hellscape that is only visible on big screens in the silo’s topmost level. Inside, 10,000 people live together under a pact: Anyone who says they want to ‘go out’ is immediately granted that wish—cast outside in an environment suit on a one-way trip to clean the cameras. But those who make that choice die soon after because of the toxic environment.

The few computers are managed by the IT department, run by Bernard Holland (Tim Robbins). The mechanical department keeps the power on and life support from collapsing, and that is where we first met savant Juliette Nichols (Rebecca Ferguson). There are a few (forbidden) relics like mechanical wristwatches or electronics far beyond the technical means of the silo’s current inhabitants, due to a rebellion 140 years ago that destroyed the sio's records in the process.

The first season opened with the murder of Juliette’s lover, George (Ferdinand Kingsley). Many twists ensued, and Holland was revealed to be a bit of a villain. In the season finale, Juliette made her own outside excursion and realized that their silo was one of many dotted across the barren wasteland; she managed to make it to another silo to survive.