Oh, come now, you really don't think it's even a little bit fascinating, Rin? You can scrub and scrub and scrub away at a bloodstain, but this thing picks up even the tiniest hint of the iron ions found in hemoglobin, and that color blue! Scientifically speaking, it's just radiant!

[ ...Uh huh. ]

Of course, I do hope that I won't have to use it, but! With this, I can be so, so much more thorough!