Singularity is the primary concept that the titular game revolves around.
Sometime during 1955, a terrible catastrophe known as "Singularity" occurred on the island of Katorga-12. This catastrophe caused the island's inhabitants to become horribly mutated mutants and creatures, such as the Mutants and Zeks. Russian experiments involving Element 99, which took place there during the height of the Cold War, seem to be the cause of the catastrophe. However, it was actually caused by Renko placing an E-99 bomb in the Singularity Tower. The catastrophe caused the opening of several timelines, which Nathaniel Renko must battle. Singularity also caused time waves, which, when occured, caused time to warp backwards to 1955.