Average Keck/NIRSPEC excess absorption spectra in percent for TOI-4010 b (first panel), TOI-4010 c (second panel), and TOI-4010 d (third panel) shown as black points. Red shaded regions mark the location of a telluric OH line that we masked in our analysis (see Figures 2 and 3). pyTPCI model predictions for the He* excess absorption signal as a function of planetary atmospheric metallicity are shown as purple (Z = 1), blue (Z = 10), green (Z = 30), and yellow (Z = 100) lines.