Environmental terrorists take control of the Thames barrier just as a major storm surge threatens to flood the London area. They demand that the British government publish a secret document entitled Aftermath but MI-5 can't find it. It's apparent that the Deputy Prime Minster, the PM is away, knows far more than she is saying. Adam meanwhile continues to struggle with post-traumatic stress syndrome. When he enters the facility to negotiate with the terrorists, he suffers an attack and is unable to function. It's left to Ros to find a way in and convince their captors that they've won and the document will be published.