Derived extinction curve from the dust in the absorber. The contribution from the quasar dust has been removed to highlight the 2175 Å dust bump from the absorber. The dashed line shows the LMC extinction curve by Gordon et al. (2003) and the dotted line shows the same extinction curve but with no bump. The position of emission lines is indicated by the shaded bands. Narrow peaks are caused by differences between the intrinsic quasar spectrum and the template used in the analysis.