The containment barrier comes down and the last thing I see before the blast hits is Derek moving toward it instead of away. The drill starts cleanly. That's what makes it worse, later … that for the first eight minutes everything is exactly what it's supposed to be. Live-fire exercise, containment field active, pairs assigned by the senior coordinator. I get Cass. Of course I get Cass. I can't prove the assignment was deliberate and so I file it under things I can't prove yet and focus on the drill. We work the exercise without speaking. She's technically precise in the way I've come to expect … nothing wasted, nothing improvised, a kind of competence that's been so thoroughly trained it's started to look like instinct. We're not friends. We don't need to be. The drill doesn't require

