ARK 564 IS A LUMINOUS ACCRETING SUPERMASSIVE BLACK HOLE THAT HAS REVEALED SEVERAL EXTRAORDINARY QUALITIES IN SOFT X-RAYS: IT IS THE BRIGHTEST NLS1 FROM 0.3-10 KEV IS ONE OF THE MOST HIGHLY VARIABLE AGN HAS A VERY STEEP SPECTRUM AND STRONG SOFT EXCESS. IN NUSTAR AO1 WE WERE AWARDED 200 KS TO STUDY THIS SOURCE ABOVE 20 KEV FOR THE FIRST TIME AND DISCOVERED THAT ARK 564 IS AS EXCEPTIONAL IN HARD X-RAYS AS IT IS IN SOFT. ARK 564 HAS A CORONAL TEMPERATURE OF 15 +/- 2 KEV ONE OF THE LOWEST EVER OBSERVED AND ALSO SHOWS AN IRON K LINE COMPLEX THAT IS SO HIGHLY IONISED THAT IT RESEMBLES MORE CLOSELY A BLACK HOLE BINARY THAN AN AGN. IN AO4 WE HAVE BEEN AWARDED AN ADDITIONAL 400 KS OF NUSTAR OBSERVATIONS SIMULTANEOUS WITH 200 KS OF XMM-NEWTON TIME AND 100 KS OF NICER TIME (THROUGH NICER BASELINE MISSION TIME). OUR LARGE MULTI-MISSION CAMPAIGN WILL PROBE THIS UNIQUE SOURCE IN THREE NEW WAYS: (1) STUDY A WELL-CONSTRAINED CUT-OFF THAT OCCURS WITHIN THE NUSTAR BANDPASS AND TEST FOR VARIABILITY OF THE CORONAL TEMPERATURE (2) ESTIMATE THE CORONAL GEOMETRY THROUGH REFLECTION AND REVERBERATION STUDIES OF THE IRON LINE AND COMPTON HUMP AND (3) TEST THE PRESENCE OF AN ULTRAFAST OUTFLOW IN AN EDDINGTON-LIMITED AGN.