Upper: detections of H₂O, HCN, C₂H₂, and OH^* in E3 covering iSHELL echelle orders 170–172. The uppermost trace is the observed cometary spectrum with the telluric transmittance model superimposed. Below are individual molecular fluorescence models color coded by species. The bottom trace shows the residual (cometary spectrum minus all models) with the 1σ uncertainty envelope overlaid and shaded. Lower: zoomed plots covering the gray shaded regions indicated in the upper panel. In this case, the uppermost trace is the telluric-subtracted comet spectrum with the total fluorescence model overlaid. Individual fluorescence models are shown below. We searched for NH₂, a potentially confounding species in this spectral region, but did not detect it. Our 3σ upper limit is NH₂/H₂O < 0.03%.