Wooden nails.

"It's not fear. It's faith. Not just religious faith, faith in something. Howie believed in conspiracies, that external forces controlled the world. Joe had dice cufflinks and a chain with a horseshoe—he was a gambler. And gamblers believe in luck. An intangible force that helps them win or lose. Gibbis has rejected any personal autonomy and he's waiting for the next batch of invaders to oppress him and tell him what to do. They all believe there's something guiding them, about to save them. That's what it replaces. Every time someone was confronted with their most primal fear they fell back on their most fundamental faith. And all this time I've been telling you to dig deep, find the thing that keeps you brave. I made you expose your faith. Showed them what they needed."