NIRSpec/PRISM spectrum of The Cliff (RUBIES-UDS-154183) at z_spec = 3.548. The orange points show NIRCam and MIRI photometry spanning an observed wavelength range of 0.9 − 18 μm; the inset colour image was constructed using the NIRCam F115W, F277W and F444W filters and shows the location of the NIRSpec microshutters. The coloured lines are the NIRSpec/PRISM spectra (rescaled using the median flux at rest-frame [3200−3700] Å) of four sources with strong Balmer breaks: two of the most luminous LRDs in the literature (z_spec ∼ 3 − 5; Labbe et al. 2024; Wang et al. 2025) and their MIRI detections (Setton et al. 2025), the triple-imaged LRD at z_spec = 7.04 of Furtak et al. (2024), and a massive post-starburst galaxy at z_spec = 4.62 (a medium-resolution NIRSpec spectrum of which was presented by Carnall et al. 2024). The dotted lines indicate the locations of strong emission line features in the different spectra as well as the Balmer limit. The Cliff shows an exceptionally strong Balmer break, a declining SED in the rest near-infrared (∼1 − 4 μm), strong H and He I emission lines, but (in comparison to the two luminous LRDs) very weak metal lines.