Simon Cheshire 
Deadline [PDF ebook] 

When Sam and Karen”s mum is dragged away by heavily armed police, their whole lives change. With no clues apart from a cryptic message screamed out as she leaves, the kids suddenly find themselves embroiled in a high-adrenalin race against time to stop a bomb blowing up Westminster Bridge. Chased by terrorists at every turn, Sam and Karen need to use all their ingenuity to survive, rescue their mum, and stop this terrible crime! Fast, furious and gripping, this is a page-turner that will hook the most reluctant reader.