Axl returns home from Europe with a new outlook on life; Sue decides to cram a whole summer of fun into two days; Brick doesn't know if he should break up with Cindy; Frankie tries to come up with an item for a time capsule.

Frankie gives away unused items from the house in the hope of getting food in return; Sue and Lexie find their apartment is being inhabited; Axl's new job as a school bus driver gives him the opportunity to look after Brick.

Frankie and Mike spend a weekend at the college with Lexie's parents, Tammy and Bennett. While Frankie has a good time, Mike says he feels like Bennett is acting superior. Frankie later gets Mike to admit he's jealous, and also embarrassed over not being able to give Frankie nice things. Meanwhile, Brick fakes being arrested for Sophomore Slammer weekend at Orson High, then needs Sue to bail him out because he has no friends to do so. Sue then tells Brick that Sophomore year isn't all he's built it up to be.

As Halloween approaches, Frankie discovers that a woman had died in the bathtub of the Heck house close to 50 years ago, and Frankie and Brick become convinced that she was murdered and, much to Mike's chagrin, attempt to track down and find the murderer. Meanwhile, Axl and Lexie become frustrated over losing their alone time when Sue insists on hanging out with them wherever they go.

Axl tries to invent a new beverage; Mike asks Sue to put together a romantic evening for his and Frankie's 25th wedding anniversary; Sue declares she won't be the person who does everything expected of her without complaint.

Frankie's mom stays with her after becoming ill; Sue suggests to Sean that they should set each other up on dates; Axl and Brick ponder what Mike actually does at the quarry.

The Hecks take a hectic road trip to Frankie's sister's house for Thanksgiving; the kids must decide which one of them will lose their job at Spudsy's.

When Axl visits Hutch, he discovers his friend has turned into a responsible adult; Sue is unable to sleep after watching a horror movie by herself; Brick enlists Frankie and Mike's help to help convince a girl to give him a chance.

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.

Now that Axl has a real job, he begins to bond more with Mike and spends a lot of time with him – leaving Frankie frozen out of their interactions; and just as Sue is about to break up with Aidan, Brad pleads with her to wait a beat until after he has a chance to win the affection of Aiden's handsome friend, Luke.

Frankie decides that she needs to find something new that she's passionate about – life's third act - and Reverend TimTom offers the perfect solution. Meanwhile, tired of hearing Sue and Brick argue because of the giant hole between their bedroom walls, Mike orders them to fix it; and after Axl refuses to let rich girlfriend Lexie pay for some extravagant outings, Lexie finds a way to fool him into thinking he's becoming lucky when money and other high priced items suddenly make their way into his hands.

Mike's wayward brother, Rusty, comes to town and presents Sue with an extravagant gift, which Mike assumes is stolen goods; Mike tries to figure out a way to reconnect with Sue; Axl blows his first paycheck on a big-screen TV.

Frankie takes Sue to a bar to celebrate her 21st birthday; Mike begrudgingly accompanies Brick to a "Planet Nowhere" convention; Axl and Hutch drive to attend Kenny's wedding.

Mike is offered the job of regional manager at the quarry; Brick suspects that he's being treated unfairly by his health teacher because of how horribly Axl treated her when he was a student.

When the Glossners steal Sue's car, the Hecks, along with the Donahues and Bill Norwood, declare an all-out war.

Dr. Fulton tells Frankie and Mike that Brick and Cindy have been making out all over the school. Mike tries to teach Brick proper dating etiquette; Sue attempts to give Sean the snow globe, and tell him how much she likes him; Frankie finds a box of unfinished thank you letters, she orders Axl to finish them, and mail them all out

Frankie is surprised but relieved when Dr. Goodwin agrees to buy all of the peanut brittle that Brick needs to sell for school. But the good doctor displays a bit of Mr. Hyde behavior when Frankie doesn’t deliver the product in an expeditious manner. Meanwhile, Axl is getting sick and tired of having Mike tell him how to run his life; and things go off the rails when Axl attempts to trade in the Winnebago and buy a car. Sue is more determined than ever to win a very prestigious and competitive hotel scholarship; and Frankie swears that she’s seeing something mysterious flying through the house.

Frankie insists that Brick ask Cindy to the prom, but her suggested "promposal" doesn't work. Brick's original idea to ask Cindy does work, and she accepts. Worried that Brick and Cindy will have no one to hang with at prom, Frankie organizes a pre-prom party with Brick's old friends from the socially-challenged group, including Arlo and Zack. This backfires when it becomes apparent that those kids have outgrown their quirks while Brick still hasn't. Brick and Cindy enjoy a private prom at the Orson Public Library, while Mike tells Frankie he is happy to have a child who doesn't think like everyone else. Elsewhere, Lexie scolds Axl for not getting Sue a 21st birthday gift. He gets Sue excited by telling her he is planning something special, but when the day comes, Axl is completely stumped. Sue is angry, but Frankie later tells her about how Axl doted on her when they were toddlers, lifting Sue's spirits again.

Determined to end the family tradition of giving Frankie a lame gift for Mother's Day, Sue and Brick try to win a trivia contest in which the top prize is a trip to London to view the Royal Wedding. When their effort falls short, they come up with a gift idea that's almost as good. Meanwhile, Axl tells Mike about a job opportunity at a national sporting goods chain that has more advancement potential than his current position, but the job is in Denver. To keep Frankie from finding out, Mike has to make up one lie after another to cover for Axl's absence when he travels to Denver for the interview.

Now that Frankie knows Axl was offered a job in Denver, she makes it her mission to sway him from taking it and moving away. Meanwhile, the usually overly optimistic Sue is depressed over Sean leaving for Ghana, without ever expressing her feelings for him; and Brick drives everyone crazy when he buys a huge amount of lawn chairs to replace the one he’s been using for nine years.

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.