In the series premiere, America's toughest trainer, Jillian Michaels, show a side of her you never knew, devoted mother, supportive partner, and comedy chops; Jillian travels to the U.K. for work, causing strain on her home life.

A family emergency distracts Jillian from her work obligations, although she does travel to New York City to rectify a busted business deal. Meanwhile, Jillian's assistant appears to be way in over her head.

Jillian invests time and money into a potential protégé, while her business partner looks to expand her brand outside of fitness; and when Jillian's son has to have a tonsillectomy, she struggles to find balance between the role of mother and provider.

Jillian has to learn to manage several work events without her trusted business partner and has to confront issues with her half-sister; Jillian and her fitness team go to Chicago for a workout convention.

Jillian works with the Clinton foundation to fight childhood obesity before heading down to Florida for her mother-in-law's 70th birthday; Jillian plans a party full of surprises, in order to make it a birthday bash nobody will ever forget.

Jillian attempts to win over her in-laws with strippers and alcohol; Jillian and her partner go to Miami for much needed alone time, but Jillian is confronted about the future of their romantic relationship.

Jillian officiates a wedding for the first time in her life, an experience Heidi hopes will change Jillian's mind about marriage. Also: The two moms take a different approach when dealing with a preschool bully; and things get heated between Jillian and anyone who disagrees with her during consumer testing of her new line of food products.

Jillian gets a deal with Cosmopolitan Magazine, expanding her empire and proving that she's more than just a fitness guru; Jillian's protégé is put to the test during a live workout; Jillian's long-term partner gives her a marriage ultimatum.