#1 bestselling author Simon Kernick will leave you breathless with his sheer storytelling power in this race-against-time thriller about a terrorist threat in London. An explosion blasts through a cafe in Central London. Minutes later, a call from an unknown terror group warns that a far greater attack will be launched in twelve hours' time. William Garrett, nicknamed "Fox," is awaiting trial for mass murder. He claims he can name the bombers--but only at a price. It's a terrifying race against time for Detective Inspector Mike Bolt and Deputy Commissioner Tina Boyd as they chase their targets across the city in a desperate bid to prevent a major atrocity before it's too late... As shocking revelations are unveiled, you'll be racing to the last page as fast as the characters in "Ultimatum." As #1 "New York Times" bestselling author Harlan Coben says, "Simon Kernick writes with his foot pressed hard on the pedal. Hang on tight "