OK Kids, sorry I bailed on you yesterday… but I have to bring a couple of  comments to the surface:

From Faithful Reader George:

Maybe this pointless, extended sidebar is really background “research” for a class paper for one of Allen’s grand kids and he doesn’t want to be accused of simply writing it for the kiddo! Or maybe Allen has just lost it a lot earlier than Dodd or Elrod!
By the way! I’m now using exclamation points for all of my sentences, just like Mark Trail! If comic strips had audio, they would all sound like infomercial talent!

Or from Greendog:

A new addition to Mark Trail’s resume … human thermometer.

So… Let’s return to the “story…”  as Carina continues to instruct Mark on “Geothermal Processes,” Gabe is getting himself tangled up in the crystal maze…  is he coming or going?  What the hell is he doing?!  And for that matter why is Mark talking about “looking for a way out,” when he had spotted one a while back in the Sinkhole??  Or was the “passage” he pointed to what led to the crystal maze?  I guess so…  Hang on everyone, we are going to be underground at least through Memorial Day…

Ah, a mere tick of the geological clock- it’s probably been “cooling” for a million years or so… Good thing they stumbled upon this formation when it was set on simmer and not roast…