 Anne Simon , a biology professor at the University of Maryland , discussed the episode in her book Monsters , Mutants and Missing Links : The Real Science Behind the X @-@ Files . Simon noted that like the worms in " Ice " , parasitic worms can attach to the human hypothalamus because it is not blocked by the blood – brain barrier . She compared " Ice " to the later episodes " Tunguska " and " Gethsemane " , with their common theme of extraterrestrial life reaching earth through panspermia . 
