Queasy Reaction

by Tyler Hinman and Craig Kasper



The image provided is a QR code (or two-dimensional barcode). Decoding the QR code using a camera phone or online decoder ([1], [2]) yields the URL http://www.mit.edu/~puzzle/26/lancebishopsqueasyreaction.png, the contents of which are reproduced below:

This grid is a Fill-a-Pix puzzle; a Minesweeper-like puzzle where each number represents the number of grid squares in the 3x3 section of the grid centered on that square which are shaded in the completed puzzle. This fill-a-pix puzzle has the solution given below:

Unsurprisingly, the completed puzzle is also a QR code. Here is a cameraphone-friendly version of it.

This QR code decodes to the answer, PEPTO-BISMOL.

Upon completing this puzzle, the following animated image is revealed on the round page: