The series takes time out for silliness with "Cryptozoology," the arguably bogus "science" of studying (using no actual evidence) the likes of the Loch Ness Monster, Bigfoot, and every other mythical creature described through dubious eyewitness reports or blurry video. An especially funny episode, "Cryptozoology" follows the feckless wanderings of so-called experts who seem more adept at buying equipment than actually using it. An interesting change-of-pace is "Manners," in which the popular perception that Americans are more rude today than they were a century ago is attacked as ridiculous, given that people routinely urinated in the street at the end of the 19th century. An etiquette expert shows us which fork to use when eating a salad, but the overall idea here is that only a handful of manners are necessary for getting through life. Three other, very serious subjects are drenched in sarcasm. One is New York City’s inability to get it together on rebuilding the Ground Zero site. The episode tracks the many instances of overreaching and mishandling the delicate task, and finds that even a national tragedy doesn’t mean the best intentions of government are free from screw-ups. In another episode about reparations, the question of whether America owes money to the descendants of African slaves and Indians is dissected with a wink. Penn and Teller also take on abstinence in a program that looks at whether sex education works, and wonder why it is that something that reduces stress and feels good the way sex does is so demonized. --Tom Keogh