Sue's senior year, the "Summer of Sue," begins with the premature removal of her braces. Meanwhile, Axl finally beats Mike in basketball and Brick tries to find the perfect backpack for school.

Mike and Frankie search for second jobs in order to send Sue to a good college, Sue and Brad produce a play for school, Brick finds some of his old "lost" toys, and Axl raids the house to furnish his new home.

Frankie and Mike are shocked when Brick announces that he wants to go to his school's fall dance. Axl has a week to declare his major but has no idea what it should be. Sue attempts to show she's more mature by drinking loads of coffee.

Brick invites a girl over to the house for Halloween, Sue tries to raise money for college with a pumpkin patch screening of "It's the Great Pumpkin, Charlie Brown," and Axl accidentally gets locked in the library.

Frankie has to wash dishes with a hose after the kitchen sink packs up. Sue has to learn a complicated dance routine so she can pass phys ed.

Thanksgiving for the Hecks at a local restaurant buffet doesn't go well when Sue feels that Mike doesn't like her boyfriend, Darrin, and Brick invites his quirky girlfriend, Cindy.

Mike accompanies Sue on a college tour weekend. Frankie leaves Brick with babysitters and a school project while she goes to watch Axl play in his first college football game.

Frankie loses her Christmas spirit, Mike unsuccessfully tries to exchange the new family Christmas tree, and a fight over Rudolph the Red Nosed Reindeer threatens to break up BossCo.

Frankie acts like a teenager when she hangs out with Pam Staggs, a former classmate who was popular in high school. Meanwhile, Brick surprises Mike by winning an athletic award; Sue pursues some odd hobbies; and Axl seeks a date with Devin Levin.

Frankie must work at Ehlert Motors for one day in order to collect her pay on an old paycheck, Mike offers Sue a part-time job at the quarry, and Mike’s dad attempts to persuade a lazy Axl to help replace the damaged kitchen sink.

Upon learning that Aunt Edie has passed away, the Hecks board a train to South Dakota to take her to her final resting place.

Valentine's Day aims its sights on the Heck kids when a nervous Brick finds out that his quirky girlfriend Cindy wants him to kiss her on the special day, Darrin asks Frankie and Mike to help out with an exciting scavenger hunt he's putting together for Sue, and Axl begins to question his girlfriend Devin's request that he not give her anything for what she considers to be a lame tradition.

The Heck family learns about Darrin’s marriage proposal to Sue…as well as her response. Meanwhile, Axl attempts to use his intro to Psych class to cure Brick of all of his quirks and tics.

Frankie realizes that she and the family forgot to celebrate Brick's 13th birthday.

Frankie fears that her innocent flirtation with Axl’s friend has been misinterpreted, and Frankie’s dad, Tag, secretly asks Mike to help him study for his driver’s test so that he doesn't lose his license.

Frankie is anxious to find out whether Sue got into college, while Sue tries to relax by making sachets. Elsewhere, Brick evicts Axl from his bedroom so he can work on his novel in quiet; and Mike denies that he was singing loudly in his car.

Frankie accompanies Brick on a school field trip and attempts to help her socially inept son make friends with a couple of boys. Devin scolds Axl for being mean to his sister. Mike gets a sinking feeling that he may have bullied his brother Rusty a bit too much as kids.

Sue gets furious with Axl for forgetting a sombrero he promised to bring her, and Frankie's attempt to resolve their quarrel only makes things worse. Elsewhere, Mike is astonished to discover that Brick was named Athlete of the Month at middle school.

A case of disrespect hits the Heck boys when Axl -- who is celebrating his milestone 21st birthday -- refuses to come home and help Mike move an old freezer, and Brick begins turning into a mini-Axl by dissing Frankie with a bad attitude. Meanwhile, Sue is torn over what to do when the manager of Chop Suey USA tries to woo her away from her job at Spudsy's.

When Frankie's uncle contacts her dad hoping to make amends, Frankie and Mike are caught in the middle of their feud. Sue turns to Axl for advice when she is sent to detention for the first time.

Frankie and Mike struggle to stay awake when watching a movie during a cozy date night at home. Meanwhile, a handsome mall employee asks Sue to her senior prom and Axl and Brick hope to find success with a barbecue sauce they've created.

Mike's incompetence threatens to ruin Frankie's Mother's Day. Mike tells Axl, Sue, and Brick to put some effort into a gift for Frankie. Frankie asks the kids how they would differ from her as parents.

Sue prepares for her graduation and worries the day won't go perfectly. Meanwhile, Brick gets the opportunity to skip a year in school and Axl grows concerned about Devin's fun summer pictures she posted on social media.