Matt Keebler on an unknown problem [v5?] in The Crystals
In Camp 4, if you hike past battle of the bulge you will eventually venture over to 'The Crystals'. Even though it was in the guidebook since I bought the damn thing, I never checked it out until Junior & Matt Keebler took me over there. There are a number of fun problems over there (see the earlier post about Team Effort) and this one is a fun, although it is unnamed according to the guidebook.