A devil is indeed waiting . . . The President is coming to London, but not to an entirely warm welcome. A fanatical mullah is offering a blessing to anyone who will assassinate the President, and though most London Muslims think the mullah has crossed the line, a few think otherwise. Urgently, Sean Dillon, General Charles Ferguson, and the rest of the small band known as the "Prime Minister's private army" are called in, augmented by an extraordinary...