Unforeseen Surge
The Bridge right outside the Southern Gate of Liegan was a key trade route for the city. And given that Beluar's army had now occupied the state, the bridge was naturally raised to prevent Wolfen soldiers from entering the city and any civilians from fleeing.
However, some had already run away, and those who ran had encountered the incoming Zhupus army and informed them about the situation.
If the Zhupus army was going to attack, then they'd definitely target the Southern Garrison first so they could gain a foothold in Liegan.
The Southern Garrison was a fortress town, but although it was called 'town', it wasn't even close to the size of an actual town.
Village was a more apt word to describe its size.
As for the river that acted as the Border between Liegan and Zhupus, it was thigh-deep, which really wasn't that deep.
It was the kind of thing that trained soldiers could cross without too much issue.