HR diagrams of the stars in our kinematically selected halo sample (in gray). The location of the stars in the retrograde “blob” seen in Figure 3 are shown in red in the large panel. The subpanels show the sequences defined by the other structures identified in Figures 2 and 4 using the same color schemes. To guide the eye we include here two isochrones having [M/H] ∼ −1.3 dex and 13 Gyr old (blue), and [M/H] ∼ −0.5 dex and 11 Gyr old (black), following Gaia Collaboration et al. (2018a).