We present a 30 h integration Very Large Telescope X-shooter spectrum of the Lyman series forest towards the z = 7.084 quasar ULAS J1120+0641 \xspace .
The only detected transmission at { S / N } > 5 is confined to seven narrow spikes in the Ly \alpha \xspace forest , over the redshift range 5.858 < z < 6.122 , just longward of the wavelength of the onset of the Ly \beta forest .
There is also a possible detection of one further unresolved spike in the Ly \beta forest at z = 6.854 , with { S / N } = 4.5 .
We also present revised Hubble Space Telescope F814W photometry of the source .
The summed flux from the transmission spikes is in agreement with the F814W photometry , so all the transmission in the Lyman series forest may have been detected .
There is a Gunn-Peterson ( GP ) trough in the Ly \alpha \xspace forest from z = 6.122 all the way to the quasar near zone at z = 7.04 .
The trough , of comoving length 240 h ^ { -1 } Mpc , is over twice as long as the next longest known GP trough .
We combine the spectroscopic and photometric results to constrain the evolution of the Ly \alpha \xspace effective optical depth ( \tau _ { GP } ^ { eff } \xspace ) with redshift , extending a similar analysis by Simpson et al .
We find \tau _ { GP } ^ { eff } \xspace \propto ( 1 + z ) ^ { \xi } where \xi = 11.2 ^ { +0.4 } _ { -0.6 } , for z > 5.5 .
The data nevertheless provide only a weak limit on the volume-weighted hydrogen intergalactic ( IGM ) neutral fraction at z \sim 6.5 , x _ { { H } \textsc { i } \xspace } \xspace > 10 ^ { -4 } , similar to limits at redshift z \sim 6 from less distant quasars .
The new observations can not extend measurements of the neutral fraction of the IGM to higher values because absorption in the Ly \alpha \xspace forest is already saturated near z \sim 6 .
For higher neutral fractions , other methods such as measuring the red damping wing of the IGM will be required .