I had heard about this incident, on which the book is based, but never knew much about it. This book is about a secret surgery that Grover Cleveland had on a tumor in his mouth. It was done on board a ship in Long Island Sound and the president literally disappeared for five days and no one knew where he was. I've just read the first chapter -- background, a whole thing about the gold standard vs the silver standard, which I understand a little better now, but not much. I learned that the White House was called the Executive Residence up until Theodore Roosevelt started calling it the White House. I also learned, although I think I knew this, that Grover Cleveland is the only president to have served two non-consecutive terms.
So Chapter One ends with the doctor confirming that the tumor in his mouth, which he had ignored for a long time, is malignant.