When Mabel questions the way Stan runs the Shack, he challenges her to a bet - whoever can make the most money in three days wins the chance to run the Shack however they wish for the rest of the summer. Mabel takes the bet and implements a new bossing method that coddles her employees and gives them the freedom to follow their hopes and dreams. Unfortunately, the results are not as expected and Mabel finds herself just trying to get back some normalcy. Meanwhile, Grunkle Stan sets off to win big money on a television game show.

When Mabel befriends a cute Merman trapped in the deep end of the public pool, she's determined to return him to his family in the ocean - even though that means her whirlwind.