The Boy From Barcelona

"It could save the world. When a runaway steals a government lab sample, the Gems are sent to the streets of Barcelona to find him. Only to discover the sample he carries could end global warming. But if Venomous finds it first, then the world's new future will come with a heavy price tag.
Olivia leads the Gems into Barcelona's Gothic Quarter, an area of narrow medieval streets and dark alleyways to find a depressed runaway who unwittingly holds the secret to earth's future. But to win the boy's trust, Olivia must face her own troubled past.
Emma's past comes back to complicate her life when the CIA captures her and demands that she tells them about the Authority's deepest secrets."