Starlight Conspiracy by Steve Voake
Alone and on the run from Social Services, 14-year-old Berry has nowhere to go. Until she meets an old man who entrusts her with a package containing a mysterious item that has unbelievable powers. It is a meeting that will change her life. For other people also want the item and will stop at nothing to get it. Pursued by the FBI and a vicious terrorist group, Berry hides out at the Glastonbury Festival where she meets fellow outcast, Elle. Escaping over the Atlantic, they soon find themselves dodging bullets in a desperate race across America. But what is in the package? And why is it so important? Hunted through cities and deserts, Berry knows that she must stay alive long enough to find the item's rightful owner - whoever, or whatever, they may be.