What's the Name of That Book??? discussion

So I read this book from my middle school library a few years ago; it is quite a strange book. A few things that I remember: A scene takes place in an underground mine where soot is everywhere and the main characters are trying to make their way out. They get these gloves that are able to stick onto the walls of the mine. Eventually, as they are climbing across, they encounter a mustache that suddenly jumps out of the soot. They are very surprised as it starts talking and tells them that it jumped off its human's face for a certain reason. Please help. I am so lost...

Mina, how long ago was "a few years?"

I was in 8th grade when I read this book, 2010-2011

Another thing: After the mustache talks to them, they release themselves from the soot covered mine wall and fall onto a glass area... The main character is a boy, I believe, and he is accompanied by another person.

The magic mustache, mr money mustache? Idk man was it like a novel or a short story?

I'm pretty sure it was part of a series. It was definitely a novel, not a short story. I feel like it was similar to the Pendragon series.

Sammy keyes and the curse of mustache mary? You'd think google would be like kids find magical mustache in a mine and pull something up right away but its like ahh hm magic mustache magic mustache yeah no doesnt ring a bell.

Hm well it was just this guy who is on a certain mission, and the mine scene is just one of the things he encounters along the way. Also, the mustache (or maybe it was a unibrow? Now I am having doubts...) was not the center of the book. It was just something that came out of nowhere kind of.

I also wondered for a second if it could be the Series of Unfortunate Events, but I cannot remember if there was a talking mustache/unibrow. I do remember Count Olaf had one eyebrow though.

Mina, are you still looking for this or did you find it?