Anthony Horowitz 
Power of Five: Oblivion 

The epic fifth and final instalment in the bestselling fantasy series The Power of Five by Anthony Horowitz.Having escaped from Hong Kong, the Five Gatekeepers — Matt, Pedro, Scott, Jamie and Scarlett — are scattered in a hostile and dangerous world. As they struggle to re-group and plan their next move, the malevolent King of the Old Ones gathers his forces in Oblivion: a desolate landscape where the last survivors of humanity must fight the ultimate battle.