Nine people have been sent to the Mars Mission Test Site to simulate a manned mission to Mars, and experiment if life is suitable there. On December 31, 2028, the day the simulation was going to end, an unknown group (Most likely Free the Soul) hacks into an operator's video feed of the simulation and releases Radical-6 into the facility. All but 3 people die, the survivors being a woman (Diana) and two other unknown people (most likely Sigma and Phi). The woman contacts the operator, ominously saying that she killed 6 people, and will likely kill 6 billion more people. This is presumably when Radical-6 escapes from the facility.
It is up to the Espers of Crash Keys to stop Radical-6 from escaping.