It's late in the evening and a young couple are comfortably settled on the sofa watching TV. Nathan, played by Osy Ikhile "Black Mirror's Emmy Award winning ep USS Callister, In the Heart of the Sea" and Gaia, played by Laura Rollins "BBC's Doctors", jokingly banter over what to watch, when an emergency broadcast alert stops them in their tracks. The warnings of an imminent missile strike should have them both in panic, but Gaia reacts in a very unexpected way. Nathan struggles to understand the whole situation, what's changed in his wife-to-be's demeanour and who the stranger on his roof is.