Mo Rocca returns back to Wait Wait in only the way that Mo can: with his numerous wild and meandering guess during the second panel round. It got to the point where, I think, Adam yelled "Bill take away a point!" when Mo made a "hail Mary" of a guess.
During Mo's Lightning Fill-in-the-Blank round, while Mo was trying to figure out the answer to the last question, Faith Salie said, "this is where the lightning round becomes an electrical storm". Adam Felber said it was more like a Van de Graaff generator.