Mapmakers

So, here's a plot outline for the first mission.
Mission 1: "Checkmate"
War with the mages is imminent, and while these scoundrels aren't expecting an attack and aren't prepared, we need to strike! But first, we need to weaken them. According to our intelligence, a powerful artifact, the Regalia of Sar-Iss, is located on the border with the Empire. What it's doing there isn't important; what matters is that this is an excellent opportunity to deprive the enemy of their "trump card" and, at the same time, bolster our army.
Let's discuss...