The Russian Vostok station is lost in the endless Antarctic night at -69°C. At the heart of this station embedded in the ice, scientists make an incredible discovery: the presence of a cavity, 3,600 meters deep under the ice cap, containing a lake. A lake that may have preserved species and microorganisms that disappeared thousands of years ago. Tasha, a young Russian researcher, Ulysse, a French exobiologist and Conrad, an American researcher, will embark in a small submarine made by the latter for a “subglacial lake exploration” mission. The press, the scientific world, all have their eyes fixed on the small team. Members of the expedition will have to travel through a tunnel more than 3,600 kilometers long, drilled through the ice. They will have no more than 24 hours to complete their mission, otherwise the tunnel will close and they will remain trapped in the ice. Upon their arrival, many discoveries await them: species that were thought to be extinct… as well as a volcanic eruption!