When Roman excels at his wizard lessons, Billie feels threatened and uses a Reverse Curse to slow him down, but it accidentally turns him into a baby.

When Billie's magic starts fizzling, she and Milo go to the wizard world for a cure. Meanwhile, the family learns the true cause of her wonky magic: a power-draining Changeling!

When an oracle from the wizard world shows up on Billie's doorstep and predicts that Billie will destroy the big summer carnival, Billie stops at nothing to change the future.

When a new student arrives and takes an unlikely interest in Roman, Billie thinks she must be the Changeling and sets out to prove it.

When Justin forbids Billie from having a haunted house, she takes Justin to Halloween future, present, and past in an attempt to help him rediscover his Halloween spirit.

When Billie gets detention, she trades wands with Milo so his spells will earn her points. But when Milo's spell goes awry, Billie must sneak home to try to save the day.

When Billie discovers that she's on Santa's Nice List for the first time, she sets out to get her rightful spot on the Naughty List back through any means necessary.

When bad boy Quentin asks Billie to the eighth grade dance, she is excited, but a wary Justin is starting to suspect that this mysterious kid may not be exactly what he seems.

When Billie's magic wreaks havoc at home, the Russos end up at Alex's apartment for the weekend. Meanwhile, Justin searches for information about the mysterious Lord Morsus.

As Alex, Justin, and Billie try to prevent Lord Morsus from fulfilling the prophecy, a long-kept secret comes to light.