He exercised for thirty minutes. He showered, dressed in khakis and a gray cotton tennis shirt, and went to his den. Beyond the windows Central Park lay in amber light and long, early shadows, thirty stories below.He switched on the computer. While the operating system loaded, he left the room and crossed the broad stone hallway to the kitchen. He toasted two slices of wheat bread and poured a glass of orange juice. He took the plate and glass back to the den, sat at the computer, and clicked open his work in progress. The book was still only an outline. It’d begun as a study of Ulysses S. Grant’s time in office, with a focus on the difference between overseeing a war and overseeing a nation, but the research had led elsewhere. Now the book was shaping up into a broader examination of every president who’d held a position of military authority before taking office. An analysis of the pros and cons regarding what that kind of experience brought to a president’s perspective. He wasn’t sure yet on which side he would ultimately come down—whether generals tended to make good presidents or not.