Prelude

Sitting on the mouth of the River Shen, the port town of Windersail has always had problems with crime, but recently there has been a rise in pirate activity. These marauders come in on fast ships, strike trading vessels before they can get away, and move away before the town guard can react.

To try and counteract this threat, the guard have hired a group of dwarves to erect a watchtower with an alarm system to alert the town guard when pirates get too close to the harbor.

However, the dwarves have been unable to tune the magic well enough. The alarm is unable to successfully identify a pirate vessel from any other and goes off when any unfamiliar ship passes by the harbor. The guards don't have the time to respond to every false alarm, but if they just choose to ignore them then the entire enterprise has been a huge waste of money.

Come to their aid. Find a way for the guards to fine-tune the watch tower so that they can tell the difference between a false alarm and a real one…