As we pressed onward while thinking that… mana reaction of humans came approaching.

  Looks like there's an empire's patrol nearby.

  『They're really patrolling the area…』


  『Guess there would be one even this early in the morning…』


  『Relaia Barondom has gathered enough forces to rout their dolls after all. It's only natural for them to be cautious.』


  I look for a hole in the patrolling network.

  Even if the network is spread wide, the other party are humans who cannot even use 『Passive Detection』.

  And the patrol is intended to alert them about possible enemy army's advance, not to prevent intrusion.

  Outsmarting this degree of network is no big deal.

  If I'm to be brutally honest, we could even go pass under the lookout's nose if we just concealed ourselves with stealth magic.

  But in order to minimize the risk of getting found, I opt for going through a hole in the surveillance network instead.

  I mean our opponent has kindly provided a network full of holes themselves, it'd be rude not to make use of those.

  And the easiest hole to exploit among those is…


  『This here.』


  I point at a spot on the map I brought with us.

  The spot is part of a river that separates Eis Kingdom from Saihill Empire.

  『River… Won't we get easily found out since it's gonna have a good visibility. There's nothing for us to hide behind on top of the river right?』


  『That would have been the case had the enemy done their homework, but it seems this place is outside their patrolling range. No one would see us even if we openly cross the river.』


  『This network is quite haphazard…』


  『Yeah. It's an evidence that the demons haven't been focusing on this territory.』


  Crossing a river is a simple matter for us, but for some reason, chant magic has no mean to accomplish the feat.

  Thus, rivers are principally being excluded when putting up a surveillance network in this world.

  Saihill Empire apparently abides by that principle, there's barely any guards around rivers.

  Of course, there are some mana reactions of what appear to be lookouts around shallow rivers that can be crossed on foot, but deeper rivers are mostly unguarded.

  The way you go about setting up surveillance network is even influenced by whether chantless magic exists or not.

  The demons would have taught these soldiers at least that much if they put any value on this region… but the demons must feel that this land is not that important enough to defend.

  I don't find large-scale traps for intercepting an army either, those demons must be fully intending to discard this region when it comes to that point.

  We headed to the river all the while.

  『Uwah, there's really no one here…』


  『I tried searching for mana reactions within one kilometer radius, and I couldn't find a soul…』


  『Makes crossing all the easier… but this river looks usable in many ways.』


  The river that separates Eis Kingdom and Saihill Empire is about 10 meter deep.

  Even a mere river can be used in many ways when it's this deep.

  『Many ways?』


  『Yeah… Say, like this.』


  I conjured up a spell and dived into the river.

  And then I pulled the thing that was in the riverbed out of the water.

  『What's… that thing? There's some kind of magic item attached to it…』


  I pulled out a huge metallic box from the riverbed.

  It's big enough to put 10 humans inside.

  It's sturdy and relatively newly made, and though it's mostly undamaged, it's missing one of its corner.

  『It's most definitely a box used to transport the dolls.』


  『Transport the dolls?』


  『Yea. They must have crammed around 10 dolls inside this box and floated it down the river. The magic item on this box is to prevent it from veering out of its set course.』


  I took out the magic item attached on the box's side and showed it to Ruli.

  Ruli has learned a lot about magic items, she's able to understand the content of this level of spell art just by looking.

  『…Its basic configuration is that of an ordinary propulsion engine, isn't it… Its course correction procedure is peculiar. Is it getting instructions from another magic tool?』


  『Yeah. The magic wiring over there is connected here. That part probably got blown away by a small explosion magic or something the moment this box arrived at its destination.』


  I point at the missing corner of the box.

  This part is probably missing not by coincidence.

  It's possible to pinpoint where the dolls were shipped out if we could figure out instructions in the magic tool used for course correction.

  Conversely, there is no way to find out where the box is from as long as that magic tool is properly taken care of.

  This river has many branches so there are many possible locations where the boxes could be set afloat.

  Finding exactly where the dolls from is not as simple as simply going upstream.

  『Ah… Could that be?』


  While I was observing the box, Ruli said that and dived into the river.

  And then she came back with something she picked up in the riverbed.

  『Found it!』


  Ruli shouted cheerfully while drying her wet clothes with magic.

  She's gripping a small splinter of magic stone in her hand.