HST spectrum of J0927−6335 (blue graph) shifted to rest wavelengths and compared to our final model (red graph) with T_eff = 60 000 K, logg = 7.0, C = 0.42, N = 0.0007, O = 0.42, Si = 0.02, Fe = 0.10, and Ni = 0.03 (mass fractions). The spectrum is dominated by strong C III/C IV lines and weaker O III/O IV lines and O V 1371 Å. The absorption feature at 1640 Å is not caused by He II, but by C IV. The continuum flux distribution is strongly affected by a curtain of numerous overlapping Fe and Ni lines, as can be judged from the dashed green graph, which is the same model but without Fe and Ni line opacities. Only a few of the strongest multiplets of Fe V, Ni IV, and Ni V are identified individually. Labels “is.” denote interstellar absorption lines. They are also included in the model spectrum.