If there really was an underground waterway that led straight to Rhine...
Then the Banshees could travel directly along the subterranean rivers to Rhine. Whether for reinforcements or relaying intelligence, it would be extremely convenient.
Although the Symbiotic Pact would drain their vitality over excessively long distances, if they traveled by water the entire way, the time the Banshees needed to make a round trip between Rhine and Castel would be very short. Their swimming speed in water was absurdly fast.
As long as they did not remain there for too long, the side effects could practically be ignored.
And if there was an underground waterway leading to Rhine, could there be routes leading elsewhere as well? That was worth exploring too.
It was good news, but from another perspective, it also brought some trouble.
For instance, seawater flowing underground.
Theus had assumed that only around Tis would the river channels have so many entrances to subterranean rivers. Now, it seemed this might be true all the way to Rhine.
Sealing those entrances was not difficult, but sealing every single one along the route... would be rather laborious.
Even with the Banshees' help.
It was hard to say whether this was a good thing or a bad thing.
However, Theus suddenly frowned. He noticed something he had always overlooked:
"Isn't the Duchy of Tis by the sea? How can there still be subterranean rivers!?"
Whether aboveground or underground, rivers would ultimately flow somewhere.
Usually, that place was the sea.
But they were already at the coast. Why were there still subterranean rivers?
Those rivers were below sea level!
Theus immediately opened Mind Link. "Is anyone exploring the subterranean rivers?"
Nini: "Me, me, me! I'm underground, Boss."
Theus: "Didn't you follow the underground river to Rhine? Why are you still over