|Harvey Plotter, who has a scar shaped like a radical sign on his forehead, must find all of the rational points on the circularum unititatus before the evil Lord Voldemorphism.
The reader follows along as Harvey and his Graphindor friends (Rong and Hymernie) prove that the points on the unit circle for which both coordinates are rational numbers (aside from (0,1)) correspond to the lines with rational slope through the point (0,-1), and then (with help from Alphas Jumblemore) parametrize these points in terms of integer parameters p and q.
The puns are heavy and the plot light, but they are probably enough to coax the reader to continue on through a very clear and precise elementary worked example in rational algebraic geometry.
Published in Math Horizons, November 2011, pp 10-14.
(This may not be the last we see of these characters. The Great Harvey Plotter Writing Contest is announced on page 2 of the same issue.)