After you create a small handful of Pic-Tac-Toes, it's no longer enough to find 9 images that fit together in a 3x3 pattern. Some of the themes have to get harder and weirder, and maybe a little irritating to the puzzle solver. Don't be afraid.
To view the past puzzles, click here. (There's also a Pic-Tac-Toe link under the "Exclusive Features" section in the right column of this page.) Your goal is the same as always: determine the theme that unites each line of 3 images. There are 8 themes total: 3 rows, 3 columns, and 2 diagonals.
SOLVED! K-Lyn of And She Was... weighed in with 7 correct themes, leaving the middle column unsolved. Bill of Shakespeare Teacher ran through some interesting guesses before locking in on the answer. Skip the comments if you want to remain unspoiled.