A fictive story presenting the USSR's final attack over the US at the end of RA2, ended with its fall and the birth of the Brotherhood of Nod.
This unit, as its name says, controls the other
mainframes from a building, thus being the heart
of a structure. Basically, this is the equivalent
of the MCT. Without it, building functions are
halted and the structure in which this unit
resides is disabled.