Written by Kevin Wald
In Phase 1, each of the first twelve puzzles has (in addition to the numerical Spookiness Rating mentioned in the Hunt introduction) a "Puzzlement Rating" which is a sequence of three letters (or "trigram"). These trigrams, when ordered properly, read:
BUI LDI NTH ISO RDE RAN ONS QUA REW ORD SQU ARE,that is,
BUILD IN THIS ORDER A NONSQUARE WORD SQUARE.So the solvers must take the solution words to the twelve puzzle and arrange them, in the order determined by the above ordering of the trigrams, into a "nonsquare word square"; that is, a diagonally symmetric figure consisting of intersecting words, with the same words across and down (as in an ordeinary word square), but which is not actually square. (One of the "solving references" pages actually goes into more detail about such figures, which are called "diagamorphs," but this is not necessary information for solving the puzzle.)
It turns out that to build the "nonsquare word square" out of the given words, three additional lines must be incorporated, as indicated by the arrows below:
ABBA BLENCH -> BE GOO ANGLER COEDIT HORIZON -> TO US NUDIST SIXTH STREAK -> THE BLOB ABLAZE KLAXON OZONE BENES
Thus, the entity to be summoned is The Blob, and the incantation is "Be goo to us."