Dream Defenders (2011)

S6E11 Gone

The Three Geeks accidentally render Buffy invisible. Seizing the opportunity, the Slayer enjoys the perks of her newfound invisibility. Meanwhile, Willow must play detective without relying on magic, putting her problem-solving skills to the test. At the same time, Xander stumbles upon Spike engaging in some bizarre workout routines, adding to the day's chaos.