Blake Crouch’s newest novel, “Upgrade,” doesn’t start with a bang but rather a slow, uphill journey that draws us in gradually. But don’t relax, because before Chapter 2 begins, the action ratchets up, and by the end of the second chapter, you’ll find you want to keep reading to find out what happens next — quickly. That level of excitement and wonder continues to the very last page. Crouch is a master at creating stories about fantastic events and the people who are affected by them. There are few real bad guys in this story; instead, there are characters who, because of their arrogance, believe they can save the world.