When Carl gets his hands on the Fuzzy Pink Bath Slippers of Heart's Desire, Yin and Yang are determined to get them back; however, Carl is held up in an anti-Woo Foo fortress and the twins are told by Master Yo not to sneak in. Nonetheless, they become spies! Will Yin and Yang be able to successfully infiltrate Carl's abode, or will he get his heart's desire?
- This episode features Carl as the main villain. However, as he doesn't do anything evil, he's not an antagonist.
- This episode is a direct parody of Mission Impossible, James Bond, and spy movies in general.
- There is a poster for "The Spy Who Fooed Me" at the end of the episode.
- As said in the poster, the name is a direct parody of a James Bond Film, "The Spy Who Loved Me."