Written by Ken Olum
The first step is to figure what is going on. The arrow and "exit to Miskatonic St" and the description of a human presence below ground are supposed to clue the subway. The text at the front is supposed to clue Davis Square station. 1984 is the year that the red line extension was opened. Porter is the deepest station and is supposed to be clued by "far, far beneath the ground". "headed for the wilderness... a short trip" is supposed to clue the next station outward, which is Davis.
At Davis Square there are tiles with pictures made by children on the wall in the patterns shown, except that the different sets are side-by-side rather than one atop another. There is a sign that says "exit to College Avenue". The childrens' names are given on the tiles, and the numbers give the position within the name to take a letter (or in one case 2 letters). The letters for each set of tiles make a word, and the words are
"It chases female student to modify as group"which is a cryptic clue for coedit.