Backstory for the Battlepass core tanks?

Fist_of_Kalinga, on Mar 26 2021 - 05:55, said:   I rewatched the video. So you have a downed plane (the ostensible reason for the "expedition" ). The tank group, setting out from the HMS Arkham, finds a German sub embedded in the ice, then comes across the plane they're looking for. It has been destroyed, but only after it had successfully landed. Then they have their "encounter". Then a crevasse opens under the tanks and dumps them in an underground base, which was apparently constructed by the Germans but was supplied by a Spanish-speaking organization, the "Sierra de la Sombra", the "Saw of Shadow" (I suspect that was supposed to be "Mountains of Shadow" but was mistranslated). The underground base is somewhat radioactive, and we see barrels of some flammable liquid labeled in German along with the Spanish-labeled crates with an inhalation warning. Once they manage to get out, we see the three tanks being watched from the viewpoint of some unknown observer through an optical device with what look like simple windage markings but no elevation.