We begin with breaking news this hour. British police have confirmed that a man and a woman who were found unresponsive were exposed to the nerve agent, novichok. This happened in the town of Amesbury, not far from the city of Salisbury where former Russian double agent Sergei Skripal and his daughter were poisoned in March. Right now, they're in critical condition. Counter-terrorism police have opened an investigation. Sarah Morice has the latest developments from London.