In 1901, a young US Army Sargent named Patrick Manhan in Washington is told by his commander that the President (William McKinley) wants to speak with him.
As Patrick waits outside the White House, he runs into an acquaintance, the British Ambassador to the US, who just got done with his meeting with the President, he tells Patrick that the President wants to know more about Germany, and that Germany would Invade New York that night.
Patrick is lead into the Oval Office where he meets the President and his Vice President, Theodore Roosevelt, they ask him about his tour of Germany 5 years ago and about the Kaiser(Emperor) Wilhelm II. He tells them that Germany has the biggest and best army in the world and is very capable of an Invasion of New York, they are stunned.
They ask him how he got such an Idea, he tells them the British Ambassador told him, they question if this is even possible.
Just then, a servant says the governor of New York and the Mayor of New York had just called with emergency news. The President goes pale and they leave at a run.
Roosevelt comes back later, it is too late he says, New York has fallen.