Rest, who had arrived in the territory of Margrave Lavender, was greeted by members of the covert unit "Sorama."
He had been informed of unsettling enemy movements and, guided by Sorama, made his way to a certain plain.
He pushed through tall grass and advanced across a desolate expanse with no game trails or signs of life.
"That's the border river...?"
Before him, past the undergrowth, lay the border river.
Rest couldn't recall the name of the river, but it was over a hundred meters wide, with a swift current and appeared quite deep. There might be shallower spots with slower currents elsewhere, but crossing from here was certainly impossible.
"Is there something here?"
"Please wait. Stay low."
"Mm..."
He did as instructed, lowering himself and hiding in the grass.
The tickling of branches and leaves against his face was unpleasant. There were insects too, and a visceral disgust rose within him. Still, this was no time for complaints.
Enduring the discomfort, he held his breath and kept watch over his surroundings.
"On the other side of this river, soldiers resembling imperial troops have been sighted repeatedly. It's as though they're preparing for something..."
"Something... something like what?"
"That would most likely be... They're here."
"!"
Sorama whispered in a low voice.
Rest turned his gaze toward the other side of the river, and there—figures who appeared to be soldiers of the Gaiselle Empire materialized. One after another, their numbers grew until they reached roughly five hundred.
"The numbers aren't large, but if that many soldiers infiltrated the kingdom and disrupted our rear, the blow would be considerable."
"...Indeed."
Rest agreed with Sorama's assessment. Five hundred soldiers couldn't conquer a nation, but they could certainly destroy supply depots and armories in the rear, set fire to towns, and create diversions. If the rear descended into chaos, the soldiers at the front lines wouldn't be able to fight properly either, drastically reducing the kingdom's combat effectiveness.
(Those soldiers cross the river and carry out sabotage within the Kingdom of Aiwood. Supply lines for food and other resources are cut off, weakening Margrave Lavender's forces fighting on the border. It might even become difficult to send reinforcements from the royal capital.)
"...If the border is breached, it's over."
"The Gaiselle Empire has greater national strength. If they break into our undefended interior, they could march on the royal capital in one sweep."
"But how are they going to cross the river..."
What did they intend to do at a place where even boats couldn't manage a crossing?
As Rest continued observing the far bank without revealing his presence... someone stepped forward before the five hundred imperial soldiers.
"That's...!"
Rest gasped. Before them stood a figure of indeterminate gender, shrouded in a deep red robe that concealed their face. Emblazoned on their chest was an inverted pentagram.
"A curse caster...!"
Rest recognized the symbol. The grim, wire-like man who had manipulated the foreign tribes—the curse caster—had worn a similar inverted pentagram symbol on his clothing.
"Don't tell me... an associate of his...!?"
"Shh... quiet!"
Rest nearly stood up involuntarily, but Sorama firmly pulled him back by the arm.
Where the two were staring... the red-robed figure with the inverted pentagram on the far side of the river raised their right hand high.
"Mmm..."
The red-robed figure murmured some incantation. An immense amount of mana radiated from the figure, so vast it could be felt even from this distance.
The next instant, as Rest stared wide-eyed and Sorama squinted in response, a spell of tremendous scale was unleashed.
"The river...!"
"It froze...!"
The swift, massive river was instantly encased in ice. An ice bridge roughly twenty meters wide spanned the water, connecting the two divided nations.
"This is bad... this is...!"
"The enemy is invading."
Crossing the newly formed ice bridge, five hundred imperial soldiers were about to march into the Kingdom of Aiwood.
"There's... no choice but to fight!"
He could not let them enter the kingdom. Rest burst from the undergrowth and cast his magic at the enemy soldiers.