A serious problem rarely appears all at once. More often, it starts as a small change that feels too minor to report: a person using a different entrance, a rumor that sounds half-true, a missing key that turns up later, or a familiar face no longer joining the group. This case study uses a fictional but realistic training center to show how small shifts in behavior, access, rumors, and movement can point to a larger risk. The goal is not to teach people to overreact. The goa