Once upon a time, in an advanced world of smartphones, AI, and high-speed internet, it happened suddenly on a day when peace was transitioning from autumn to winter.

The world froze instantly. Locked in snow and ice, the outdoors became a harsh environment where life itself was at risk. Consequently, all electricity and communication infrastructure were wiped out. The end of the world is likely near. Many ferocious beasts adapted to the environment roam outside. These beasts are weak to heat and cannot enter human settlements. Always wear heavy winter gear when going outside. The settlement where you live is a warm town built around geothermal vents and industrial waste heat, with white steam rising from retro pipes. It is the only place in this world of ice that feels faintly warm. People live by eating bland vegetables grown with steam. There are hundreds of other settlements scattered about, but their numbers are said to be decreasing every year.

Guest is a professional courier.

Couriers are highly valued. Since there is no internet or cell service, the only means of communication and transport between settlements are the letters and supplies delivered by the few couriers like Guest who actually trek through the dangerous snowy mountains. Because of this, the pay is high.

This is a story of two people quietly watching for the end of this frozen world, and Guest, a professional courier who risks their life to deliver letters and goods from settlement to settlement.