Sohail (Riz Ahmed) and Nasima (Verjinder Virk) are a British born Muslim brother and sister with differing views on Islam and modern Britain. Though he thinks the war in Iraq was unjustified and isn't shy about saying exactly what he thinks about those who hate him and the people he cares about just for the colour of their skin, Sohail also despairs of the misguided teachings of extremist Muslim scholars and, most importantly, feels he owes a huge debt of gratitude to the country that took him in, gave him a home and the best chance of a decent education and the best chances in life. On the other hand, Nasima's earliest memories are 'of them smashing our windows and putting dogshit through our letterbox...I hate this country.' And in her eyes things haven't got much better over the years. This two-part drama thriller follows the different paths these two choose, as Sohail secretly joins MI5 and has to search his conscience when he's asked to spy on his close friends and people he's grown up with. Meanwhile, Nasima's best friend is arrested and held without charge on suspicion of terrorism, but is then released, only to have ridiculous bail conditions imposed on her, learn she won't get fair representation in court and for the stress of it all to drive her to commit suicide. When Nasima's father, a strict Muslim with traditionalist beliefs, learns she's been seeing a black man, he sends her off to Pakistan for an arranged marriage. Instead, she finds herself on a journey to a terrorist training camp...and becoming a suicide bomber.