Marshall begins his new job at Barney's law firm and quickly finds that Barney's colleagues are crude, obnoxious and laddish, mocking everything from his packed lunch to his fiancée. However, he doesn't want to give up, and learns to adapt.
Trouble arrives when Larry's first call on his new cell phone leads to Richard Lewis's girlfriend succumbing to a peanut allergy a week before the Emmys.
When Magistrate Hale discovers that it was Isaac who broke the witches circle, it's up to John to save him. A power struggle arises within the hive, forcing Mary to assert her authority with potentially deadly consequences.
The sisters come to the aid of Mylie, a mermaid-turned-human who needs their help to escape from a pact that she has made with an evil water demon called the Sea Hag.
A face from John's past comes to Salem, and Mary's plans nearly come apart when she loses control of Mercy Lewis. Elsewhere, Mary's most trusted ally, Tituba, is forced to deceive John to eliminate a threat that endangers her mistress.