By Alex Rosenthal

The solver is presented with two images of heads, and thirty-three TIL statements.

It’s possible to transdelete a word in each statement to make it true. For example, “A man began to hiccup after a goth fell on him, and he wasn't able to stop until 68 years later.” GOTH = HOG + T.

All of these statements are facts that can be found within TED-Ed videos. The thirty-three cells within the first image of the head all contain stills from those same videos. Identify them. The head image can be found at the beginning of every TED-Ed video.

Place the added letters from the TILâ€™s into the second image of the head, in the corresponding spot to the still from that video. For example, the lower left still is from the video “Could we actually live on Mars?”. The added letter in that video was a T (TRAMS = MARS + T), so place a T in that spot in the second head image.

Reading off the thirty-three letters in the order suggested by the black dots between cells in the second image yields the clue phrase: TIL HANDS CAN COUNT USING BIRYANI AT END.

Iterate on the transdeletion technique to get TIL HANDS CAN COUNT USING BINARY AT END.

This is a reference to the TED-Ed video “How high can you count on your fingers?”. At the end of that video (at time 3:57), solvers will find thirteen hands around a computer chip, cycling through a sequence of binary finger positions. Either by pausing, or focusing on an individual hand going through the full sequence, solvers can translate the binary into decimal, then into letters (00011 = 3 = C), yielding the answer CRANIOGRAPHER.