"Are you sober?" "I'm afraid you've got the wrong impression of me altogether," said Spade. "I drink and sometimes heavily, but I'm not a drunk." Heavy drinking was part of his job. As an agent he had to play many parts. But he'd been well trained, an artist at his job.
Alone on a small woodland path and around the next bend you could be in any other time. You could relive another part of past life. Your mind wants you to. You have no control. It's frightening and tiring, and all you long for is A Quiet Place. This is the dark side to the meaning of mind over matter.
Commander Spade reaches such a pinnacle along this path. He knows that only the tiny little pills can keep him cuddled in reality. He must seek the more secure refuge in A Quiet Place.
The book almost reveals itself near the end when Spade senses he's with the presence, his executioner.