Top panel: rest-frame UV spectra between 1150 and 1400Å of the Cosmic Horseshoe, a z = 2.38 gravitationally lensed galaxy from the MEGaSaURA sample (Rigby et al. 2018). Overplotted in red is the best-fit STARBURST99 stellar continuum fit. This fit measures E_B−V = 0.16 mag. The error spectrum is included underneath in dark green. Bottom panels: Si II 1190 Å doublet (left) and Si II 1260 Å singlet (right). The corresponding from the Si II 1260 Å line is 0.77. Vertical dashed lines indicate the zero velocity of the various strong ISM metal absorption lines (labeled in the upper panel).