City located in the southeastern Ural Mountains in Russia. In 1957, the cooling system of a radioactive liquid waste storage tank at Mayak malfunctioned and exploded. Large quantities of radioactive waste were released. The contamination spread over an area measuring approximately 100 kilometers long and 9 kilometers wide. During the 1970s, a former Soviet scientist who fled to Britain disclosed in his writing that more than 10,000 people emigrated as a result of the disaster. After nuclear disarmament, plutonium and highly enriched uranium removed from the nuclear warheads were transported to Chelyabinsk-70 from all over Russia and the city was exposed to even more radioactive contamination.

Chelyabinsk-70 was the birthplace of Elisa, FOX Unit's medical chief in 1970, and ESP group member, Ursula. Caught up in the Ural Nuclear Disaster, they acquired unique abilities.