The Swift/XRT hardness curve of Mrk 817, covering the mission periods with dense monitoring. The soft band is defined as 0.3–2.0 keV and the hard band is defined as 2–10 keV. The hardness curve is based on the number of counts in these bands, and is defined as (H−S)/(H+S). The dashed blue line indicates the date of our NuSTAR exposure. The unprecedented hardness at this time is consistent with obscuration acting in the soft X-ray band.