Chicago Party Aunt Diane is an idolized troublemaker with a talent for avoiding adulthood — and a soft spot for her soul-searching nephew.

Mark overhears Bonnie saying he won’t go the distance in the Chicago Marathon. Daniel is delayed in meeting the CEO of Kreativ Jus at the finish line.

Diane is thrilled to see the ’85 Bears re-create the Super Bowl Shuffle at the Beefy Awards, but her son, Mikey, plans a dinner party for the same night.

On Christmas Eve, everyone has plans that don’t involve Diane — until a glitchy voicemail has her panicked family searching hospitals to find her.

An unwanted senior citizen discount at Ribfest sends Diane on a quest to reassert her youth that runs into just one problem: she’s getting older.

Diane and Bonnie’s parents, Big Lou and Peg, fly in to tailgate at a Bears-Packers game, where a longstanding feud between rival families is reignited.

Hoping to score his first kiss, Daniel suits up for the Halloween costume party at Roscoe’s Tavern, where Diane blabs a big secret about Gideon.

Diane studies for a corporate test while Daniel moves in with her and begins job hunting, leading to some unfortunate encounters with city wildlife.

After one late night too many, Diane worries she’s out of step with the times but vows to school her nephew in living life.

Debbie, sad and lonely after Aunt Ginger leaves, steals a little boy from a birthday party. In classic Gallagher style, the family hatches a plan to return the toddler safe…