Invisible Traces

Exploration Stage: Octopus Citadel
From: Mr. Black
Description: Violet’s dog’s collar replacement operation must be perfect. Violet is very attentive, and she’ll immediately notice if the work is done carelessly. Let’s look for a nano-soldering iron to attach the bug to the collar as discreetly as possible.
Completed: Great, you’ve found the nano-soldering iron. Let’s solder the bug directly into one of the replacement collar’s links... The main thing is not to damage the device itself. The nano-soldering iron is convenient because it leaves no trace at all when it solders parts together.