A woman has to deal with feelings of grief and guilt after her husband and son die in a terrorist attack. A young London mother (Michelle Williams) waves her husband and son goodbye as they head off to see a local football match. As soon as they're gone, she entertains local news reporter Jasper Black (Ewan MacGregor), with whom she's been having an affair. As the two begin making love, a news flash on the television informs them that a suicide bomber has attacked the stadium which her husband and child were attending. In a blind panic, the woman heads for the football ground, where she runs into her late husband's boss, police officer Terence Butcher (Matthew Macfadyen). In the following weeks, as she attempts to put her life back in order, she's introduced to, and befriends, a young boy (Sidney Johnston) whose father was involved in the attack.