After years of being at their kids' beck-and-call and never having time for themselves, Frankie and Mike decide to take charge of their lives and regain control over the Heck household. But Axl, Sue and Brick don't plan on going down without a fight.

Frankie insists that the family go on vacation together before school starts; Mike and Frankie remember their honeymoon, which was ruined by Nicky (Ray Romano), a guy Mike knew in high school.

Frankie insists the family take a few days of vacation before school starts. But Mike's suggestion of a camping trip brings back bad memories of their honeymoon camping trip.

As the Heck home begins to literally fall apart, Frankie and Mike consider leaving homeownership behind and moving the family to an apartment. Meanwhile, Axl tries to fake Frankie out by pretending that he's sick in order to get out of taking a school test - and must later convince her that he's well enough to attend a party that evening; Sue and her ex-sort-of-boyfriend, Brad, volunteer to prepare a school skit about showing the dangers of texting and drinking while driving; and Brick tries to offer a little bit of levity by spouting off Shakespearian quotes.

With Indiana hosting the Super Bowl, Frankie is devastated when she hopes to land a plum assignment as an official volunteer and ends up with a less-than-stellar position. Meanwhile, the entire Heck household takes advantage of the Donahue's new car while they are out of town, and a scary, close call with the car causes Sue to profess her true feelings to her new boyfriend, Matt.

Frankie and Mike decide to try a fresh approach to Valentine's Day by having dinner out with friends. But a clueless Mike angers Frankie by refusing to present her with a simple romantic gesture. Meanwhile, Axl can't think of a life-changing moment that's occurred in his life when he's assigned to write a school paper on the subject, Brick is tasked with writing a report on love, and a hapless Sue doesn't understand why her new boyfriend has suddenly turned into a bad kisser.

Frankie and Mike run into old acquaintances, Sue gets several dates to the prom, and Brick gets Axl's help for a book report.

At the annual homecoming tailgate, Frankie worries that her mother will ruin things, Sue takes a familiar role, Axl is sick as a dog, and Mike asks Brick to help him win the cornhole tournament.

Mike enlists Axl and Brick's help to throw a surprise party for Frankie's 50th birthday. Meanwhile, Sue is mocked after posting a flyer for her missing sock in the dorm laundry room; and Coach Babbitt is determined to turn Brick into an athlete after he turns in a project about how he can't play sports.

While the Hecks take Brick to his first movie in a theater, Mike and Frankie fight over a conversation with friends, Sue runs into an old crush who has some surprising news, and Axl discovers that he shared an awkward moment with a friend.

The Hecks decide to take a Spring Break vacation with the Donahues, but Frankie soon discovers that both families are going through their share of big problems.

As Halloween approaches, Frankie is taken aback when she discovers that, if the circumstances ever arose where she and Mike got divorced, the kids would all choose to live with Mike. Meanwhile, Sue tries everything in her power to get her room back from Brick, and having to be so nice around girlfriend April all of the time leads Axl to lash out at his family,

Frankie decides that April is not good enough to be with Axl and does anything she can to keep her out of the annual family Christmas photo. Frankie must fight for Axl's attention when he announces that he will be spending Thanksgiving with April.

The Hecks find themselves spending New Year's Day attempting to stave off a zombie apocalypse in the Orson Escape Room, desperately trying to beat the Donahue's record of getting out with more than one minute, eight seconds to spare. Meanwhile, Brick is convinced that the mild-mannered man assigned to the family's Escape Room group is really the famous author of the "Planet Nowhere" books; Sue divulges a secret about herself to Axl that's she's been keeping since childhood; and Mike is stunned when Frankie reveals that she had a romantic dream involving Frank Sinatra.

Frankie remembers she has to come up with something to place in the time capsule; Bill Norwood informs Mike that he and Paula are separating; Brick tries to win Cindy back; Axl volunteers Sue to be his personal assistant.

Frankie and Sue are devastated when Axl informs them that he's not going to church; Mike goes to war with the Glossner kids after they keep defacing his giant inflatable snowman; Brick attempts to wrap his first present.

Sue admits to Frankie that she kissed Sean Donahue at the Christmas party; Mike forces Axl and Brick to take a drive with him and Mike's dad.

It's the Orson showdown of the century when the Hecks - along with the Donahues and Bill Norwood - wage a war against the Glossners after they steal Sue's car.

Frankie makes it her mission to sway Axl from taking the job in Denver; Sue is depressed over Sean leaving for Ghana; Brick buys a huge amount of lawn chairs to replace the one he's been using for nine years.

After nine hilarious and heartfelt seasons, a Heck leaves the nest as the family takes a road trip to Denver, where Axl will start his new job – and new life away from home.

The series concludes as the family escorts Axl to Colorado. Meanwhile the long affair of the snow globe and its relation to Sean and Sue's relationship comes to a head.