After Piper leaves on a business trip, it doesn't take long for some friction to appear between Prue and Phoebe. However, they set their differences aside when they run into a ghost of a serial killer who's looking for a revenge against people who sentenced him with a death penalty. Meanwhile, the many unsolved crime cases are finally starting to catch up with Andy when people from Internal Affairs take an interest in them.

The sisters are about to go on a relaxing weekend getaway to Cabo, when a mortally wounded Leo shows up and asks for their help to save a young woman who's being chased by a darklighter. Desperate to save Leo, Piper casts a spell that swaps their powers, however in doing so, she accidentally swaps the powers of Prue and Phoebe as well. Meanwhile, pressed by an Internal Affairs investigation Andy decides to leave his job in order to protect Prue's secret from being exposed.

A warlock repeatedly attempts to kill the Charmed Ones, with a help from demon Tempus turning back time after each failure so that he can try again. However, because of the endless time loop and her power of premonition, Phoebe experiences a number of strong cases of déjà vu and is able to figure out that there are evil forces after them.