A migrant boat battles through the rough Mediterranean. Its passengers are desperate, starving and scared. They are also being ruthlessly targeted by the SAS. Islamic State militants are smuggling themselves into Europe using these boats. Only by locating such men before they make it into the UK can the Regiment stop them committing their acts of terror on British soil. When one of these migrants reveals plans for a sickening Christmas Day atrocity in London, SAS operative Danny Black is tasked with infiltrating the most dangerous theatre of war in the world: Islamic State heartland. There, he and his team must lift a brutal IS commander - the only man who knows all the details of the London attack.