Blackwater Lake, a vast expanse of water along the western edge of the grasslands, lay embedded in the endless green like a deep blue sapphire. The lake glittered beneath the sunlight, and its waters took on a unique dark-blue hue from the silt on the lakebed and the vegetation around it, hence the name "Blackwater."
Four fortresses stood like the iron fists of giants, firmly embedded at four strategic points along the lake shore: Iron Wall Fortress on the northern shore guarded the passage into the northern wastelands; Dawn Fortress on the eastern shore faced the heart of the grasslands with an expansive view; Dusk Fortress on the western shore was hidden behind the hills by the lake, making it easy to defend and difficult to attack; and Stone Fortress on the southern shore faced the southern trade route, controlling the flow of supplies and intelligence.
Each fortress had high stone walls lined with watchtowers, with cannons poking through the crenellations and overlooking the lake and surrounding grasslands. Though the fortresses stood several miles apart, they formed a tight defensive net through gunboats on the lake and scouting squads on land. Aldo Army soldiers rotated shifts around the clock inside the fortresses, alert to any unusual movement near the shore.
To improve mobility and fire support, Aldo Army had built a small shipyard by the lake. The craftsmen worked day and night, turning timber and metal materials shipped from the forests of the Northern Three Territories into one exquisite gunboat after another. The boats had long, narrow hulls and shallow drafts, making it easy for them to weave through Blackwater Lake's shallow bays and reed beds. Each gunboat carried several light cannons, with one mounted at both the bow and stern, allowing it to attack enemies ahead and on the