The scene is set for a huge funeral in St Patrick's Cathedral in New York. The rich and the famous from all over America - and beyond - have arrived to honour a former First Lady after her sudden, unexpected death.

Then follows an attack that was three years in the planning. Hostages are taken - the ex-President among them - ransoms demanded, a couple of hostages shot to show the kidnappers mean business.

It's all brilliantly and chillingly co-ordinated, and Michael Bennett, the detective in charge of the case, knows it will be his biggest ever challenge.