Christopher and Adam were deliriously giddy in October 2004 as they splashed accelerant onto the floors and walls of the main block of Hafodunos Hall—a residence in disrepair since 1993. The glint in their eyes was nothing short of evil as their lighted matches hit the floor.

Flames licking hungrily at their heels, they didn’t stop running until they knew they were safe. Cheating death for profit had become a ritual as they flopped down on the slope for a smoke to admire their handiwork...