Metro:Last Light takes place one year after the events of Metro 2033, proceeding from the canonical ending from the novel, ending where Artyom chose to call down the missile strike on the Dark Ones. A hidden ‘Karma’ system based on the players actions during the game, such as shooting surrendering enemies or killing non-hostile mutants, or listening to NPC conversations or donating to beggars in stations, is present throughout the game, but it’s results are not revealed until the last level.