In an alternate world, a dragon once attacked a community and only stopped on the condition of periodic human sacrifices. The community agreed as they had no other way to stop the dragon.
Over centuries, society adapted to this and has developed an entire culture around the dragon, including religious beliefs that justify the sacrifices and government bureaucracy that facilitates them and compensates those left behind. The sacrifices are frequent and large enough that almost everyone in the community has lost a loved one during their lifetime.
Science has now advanced to the point where a material has been developed that can pierce the dragon's scales, making it possible to launch an attack on the dragon. However, the attack may fail, and the dragon may retaliate against the whole community