The fourth and final DLC for "Battlefield 1", the "Apocalypse" DLC, is centered around some of the most brutal battles of the Great War. The DLC was released on February 20, 2018, containing five maps, six guns, and a new game mode, among other additions. The three infantry-based maps of "Apocalypse" reflect three of the bloodiest battles of World War I; Caporetto set in present-day Slovenia, Passchendaele in Belgium, and River Somme in France. The DLC brought no new factions to the game, but introduced a new game mode titled "Air Assault" in the remaining two maps. These two maps, both only plane- and zeppelin-focused, are named "Razor's Edge" and "London Calling." While both maps feature combat above detailed landscapes (Razor's Edge taking place in the Alps and London Calling occurring over the city of London), neither are based on factual battles.