MMMM a steaming hot mug of Plasma.

   He was intentionally ignorant of what the FOOF would do.  Blind to its ability, once the coolant had been stopped, to burn a hole though the earth and at the same time turn that very same earth into magma.  Hot molten goo that was so credibly reactive it would melt a hole in a metal pipeline and fill it with hot oozing ultra reactive plasma.  The exothermic magma would come in contact with water, and that would empower a secondary reaction, and burn through the pipe destroying a vast length of it.  All this was supposed to happen with out a surface disturbance, and hopefully the destruction of the mostly forgotten unused pipeline would be undiscovered, and in fact be a perfect trial run for the main event.

Border crossing

    The following images are from the Thirteenth century border crossing between the terrarians (us) and the subterrarians ( the highly intelligent hominids that dwell below the surface.  These decorative fortified crossings served as ceremonial exchange venue between cultures.  Sometime in the fifteenth century contact was lost with the subterrarians,  These structures are all that remains of  that exciting period in history.