The first step is to solve the arrow heart sudo-kurve puzzle (or I suppose check the answer key if you have the book, but why spoil the fun).
The circles and lines on the dance card should remind you of arrow sudoku clues but without complete paths. You must lay the dance cards on the solution in the only way that valid "two step" arrow clues exist with two cells adding up to the circled digit. This concept was simplified by actually providing the arrow paths in a hint, but still proved pretty challenging.
If the arrow paths don't immediately suggest the proper decoding, the phrase "frantic waving" in the flavor text is meant to indicate flag semaphore, one of the decoding schemes on the linked list. Going in order from 1-12 gives the message FRIDAY SQR. NOS. or "Friday Square Numbers". (Note: I had to use the existing solution of this puzzle to code a message; while most letters could be made, the U was not possible, so neither PUZZLE nor SQUARE could be fully spelled out, leading to the choice of abbreviated message.)
fridaysqrnos.html is the next page.
