Beat me to it! It's also a great episode to watch from a Bayesian standpoint, because throughout it, you see people having to radically shift their views because they see extremely improbable evidence.

Since you've already spoiled it, I want to highlight one scene in particular: Kyle, Stan, and a Truther guy are taken to the White House, where Bush and his cabinet (falsely) admit to having orchestrated 9/11 and then execute the Truther (which later turns out to be fake too). All Kyle can do is respond with, "REALLY?", more incredulous each time.

Link again, thanks Jayson_Virissimo for posting it.