Context : The lithium abundance in turnoff stars of the old population of our Galaxy is remarkably constant in the metallicity interval -2.8 < [ Fe / H ] < -2.0 , defining a plateau .
The Li abundance of these turnoff stars is clearly lower than the abundance predicted by the primordial nucleosynthesis in the frame of the standard Big Bang nucleosynthesis .
Different scenarios have been proposed for explaining this discrepancy , along with the very low scatter of the lithium abundance around the plateau .

Aims : The recently identified very high velocity star , WISE J0725–2351 appears to belong to the old Galactic population , and appears to be an extreme halo star on a bound , retrograde Galactic orbit .
In this paper , we study the abundance ratios and , in particular the lithium abundance , in this star .

Methods :

Results : The available spectra ( ESO-Very Large Telescope ) are analyzed and the abundances of Li , C , Na , Mg , Al , Si , Ca , Sc , Ti , Cr , Mn , Fe , Co , Ni , Sr and Ba are determined .

Conclusions : The abundance ratios in WISE J0725–2351 are those typical of old turnoff stars .
The lithium abundance in this star is in close agreement with the lithium abundance found in the metal-poor turnoff stars located at moderate distance from the Sun .
This high velocity star confirms , in an extreme case , that the very small scatter of the lithium plateau persists independent of the dynamic and kinematic properties of the stars .