Tired of doing Enchantra's evil bidding, Salem runs off and magically takes on a human form after accidentally falling into the cauldron made by Hilda and Zelda for a transformational potion. However, when Enchantra has a vicious shadow spirit do her bidding, Salem must choose between a free or feline life as Enchantra's spy and servant.
Enchantra orders Salem to lure Zelda and Hilda to the portal, where she intends to banish them to the dark valley of nothingness. Sabrina would then so distraught, she would have to choose to live in the magical world forever with Enchantra. When Salem rebels against her, the evil sorceress sends a vicious shadow spirit through the portal in his place to casue havoc and chaos in Sabrina's life in the mortal world. After enjoying some time as a free man called Sal, Salem agrees to become a black cat again and resume his role as spy and reliable servant to Enchantra.
- The title refers to the expression, Who Let the Cat Out of the Bag?
- Sabrina cares about Salem very much and worries about his safety and wellbeing.
- All cats/felines are said to be descended from almighty Egyptian gods and were mainly kept as faithful pets for the royal family.
- Enchantra raises her level of evil from then on . She intends to come up with even more sinister ways to make Sabrina's human life even more insufferably miserable.