The three-arched bridge

When the construction of a bridge built to link the Balkans to Europe is repeatedly and mysteriously sabotaged, an old ballad starts making the rounds at local taverns. The bards sing of a legend - a woman immured in a castle wall to prevent it from falling. Some say the bridge is being damaged by local ferrymen, others blame the vengeful water spirits. But this is a town where terror and superstition reign and a solution must be reached. So it is decreed: a willing person must be plastered into the bridge.