Two experiments activate at the same time while Lilo and Stitch are arguing. Lilo and Stitch insist that they each can catch an experiment without the other. Meanwhile, Jumba and Pleakley make a bet to see which one will capture an experiment first, and Gantu forces Reuben to help him catch them both. The race is on because Jumba theorizes that the world will be doomed if the two elementally opposing experiments touch each other, they will destroy Earth. Eventually, Lilo and Stitch team up together again and help each other capture the experiments each was after using the "tools" given to them by Jumba and Pleakley. Lilo repurposes the experiments to create a new island.
- Moral: Always work together.
- Yin is female and Yang is male.
- Lilo erroneously referred to Yin as a male.
- Yang is the only experiment besides Stitch to escape a net by himself.
- Both of their names are derived from the concept of Yin and Yang.
- Reuben was reading a book titled Escape from Sandwich Mountain, an allusion to Disney's 1975 movie Escape to Witch Mountain.
- Though Yin apparently has no mouth, a mouth is seen on her in "Angel" when she and other experiments carry Stitch out of a ship, which Angel had lured him into. A mouth is also seen on Yin in a few scenes of "Slugger", especially when she and the other experiments watch Lilo and Mertle argue over the game rematch.