The town of Elmo throws Marin a huge birthday celebration, but the unexpected arrival of her fun-loving younger sister, Liza, conjures up some unexpected insecurities for Marin. Now that Ben has asked Theresa to move out, tensions rise between Theresa and Sara, whom Ben is now dating. Meanwhile, Buzz finds Patrick's father's plane that had disappeared 26 years ago -- opening up Patrick's hope that the father he has never known could have survived and be alive somewhere.

Unbeknownst to Marin, Jane leaked an excerpt from Marin's new book on men to The New Yorker magazine. Now Marin is forced to defend her career to Jack, the unwilling subject of her work. Meanwhile singer-songwriter Jewel stops into the Chieftain when her car breaks down, and runs into Theresa, who turns out to be her former bandmate, and Patrick's mom, Celia and his new step-mother, Mai, go head to head in an alpha showdown for the role of "top mom,"