VLT X-shooter spectrum of ULAS J1120+0641 (black), covering restframe wavelengths between 850 and 1400 Å. The spectrum has been binned to a pixel size of 150 km s^-1 using inverse variance weighting. The observed wavelengths of Lyα, Lyβ and the Lyman limit are marked. The only transmission detected in the spectrum is confined to spikes over the wavelength range marked by α, in the pure Lyα forest, corresponding to the redshift range 5.858 < z < 6.122 (Sect. 3.2). The corresponding wavelength range for Lyβ absorption is marked β and lies blueward of the restframe Lyman limit. Plotted as the blue dotted line is the (scaled) total system throughput curve for the ACS F814W filter.