Mary gets her driver's license, but can't parallel park. She cried during the test because she couldn't park, so the teacher passes her anyway. Meanwhile, Simon learns that his girlfriend Deena had leukemia when she was five years old, but went away. Although, every year she has to go for a check-up to make sure the disease didn't come back which worries the both of them. Also, Ruthie calls a woman who she thinks is a psychic and asks her if Deena is going to be all right. Lastly, Eric's sister, Julie is back in Glen Oak and she has a new job and is starting a life of her own now. Eric and Matt want to help her get settled in Glen Oak, but are trying to help a little too much.

The Colonel and Grandma Ruth return from being out of the country for six months. Simon surprises his grandparents with his new haircut. Matt decides to move out of the house and gets his own apartment with John Hamilton. Aunt Julie's new husband Hank gets Matt a job at his hospital working in the cafeteria. Eric begins to suffer a mild heart attack due to the stress from his job.

Eric and Annie put on their counseling hats when a very pregnant Julie appears on their doorstep prepared to leave her new husband Hank. Eric decides to take Hank out to dinner to discuss their issues. While they are at dinner, a very pregnant Julie goes into early labor. Unable to transport her to the hospital because Simon and Mary are out to dinner and Lucy is on a date, Annie does her best to calm Julie down. Hank and Eric return to the house just in time for the birth. Julie delivers a baby girl. Grateful for Eric's effort, Julie names the baby after him: Erica. Meanwhile, Lucy is disappointed when her date expects her to be 'the man', and Simon attracts the attention of an older female admirer.

Rev. Eric Camden counsels a sexually molested girl to help her express the rage and pain she's been hiding from her family. This dark secret that Mary knows about weighs in on her, which brings her to open up to Lucy. Meanwhile, Simon and Ruthie learn the power of communication with their friends and classmates. Also, Matt helps Hank reveal an important personal secret to Julie before his mother visits.

Tensions run high as a doubtful Julie lets Mary baby-sit Erica, only if Mary has no visitors. But when Frankie (guest-star Chyler Leigh) comes by and begs Mary to take care of her baby Mercy, Mary can't resist helping her. Then, Mary is then caught with an open bottle of beer while babysitting. Meanwhile, Lucy volunteers to chaperone Ruthie's sleep over and to watch the twins. Also, Simon is on a quest to change his image and does this by piercing his ear. Matt pursues a woman who wants nothing to do with him. Also, Eric and Annie clash with Mary's disreputable friends.

Still unemployed and bills mounting, Mary continues her downward spiral to rock bottom as Eric and Annie fight about how to effectively deal with her numerous lies and immature behavior. Meanwhile, the fear of what may happen to Mary starts to take toll on the rest of the whole family. By this, it is prompting the children to break open the twins piggy banks to help Mary pay her bills. To get the credit card company to stop calling, however, they are forced to make a risky decision. During all this, Mary CONTINUES to ignore her responsibilities.

Eric and Annie desperately try to figure out how Mary managed to pay her credit card bill while the kids team up to throw them off the scent. When the parents vs. children game finally breaks down, drastic changes happen. After learning that Mary stole from the twins to pay her bills, Eric and Annie come to the heart-breaking realization that they must take drastic action to help their misguided daughter and to protect and preserve the family. The Camden's gather to confront Mary with their feelings of hurt and betrayal and their conclusion to send her away to Buffalo with ""The Colonel"" and Grandma Ruth.

Lucy and Robbie argue over who should tell Mary about their emerging relationship. Meanwhile, Matt worries that a young woman in his study group might be a victim of physical abuse at the hands of her belligerent boyfriend. Eric's sister Julie shows up at the Camden house with her toddler Erica and annoys Annie as she tries to prepare a lesson for her class. Simon meets up with Sasha and they both try to catch up on their personal lives.

Matt and Eric meet with Rabbi Glass to discuss wedding plans, and Eric learns that he is playing a smaller role than he had originally planned. Annie prepared for fewer guests to attend the rehearsal dinner and gets very flustered when she does not have kosher food. Ginger and Charles are prepared to fly to Glenoak, but Charles get's lost at the airport. Simon gets angry when Matt asks Robbie to be his best man. Meanwhile, Ruthie tells Robbie that she wants his room for herself after Matt moves out. Ben proposes to Mary, but he gets an unexpected answer.

When a nasty thunderstorm rolls through the region and threatens to postpone Lucy and Kevin's wedding, everyone scrambles to make it to the church in time. Mary barely catches the last flight in and brings Matt with her. Chandler and Roxanne rush to pick up Ben and his mother who are stranded at the airport in Las Vegas, but tensions run high and a fist fight breaks out; and Matt gives Lucy some very special brotherly advice when she confesses to pre-wedding jitters.

Prospective homeowners Lucy and Kevin are ready for a fight to the finish when they learn that Chandler and his soon-to-be-adopted son Jeffrey are their rivals in a bidding war on a house. However, the conflict sparks an idea with Eric and Annie who decide to use their savings to buy their house from the church. Meanwhile, Ruthie is upset with Martin because she thinks he will get the garage apartment instead of her when Lucy and Kevin move out, and Peter suspects that his dad might be having an affair.

Lucy, upset that the family hasn't given her any gifts for the baby, convinces Matt to take her shopping even though she is supposed to be staying off her feet. While shopping, the two get stuck in an elevator and Lucy goes into labor, putting Matt's medical skills to the test. Meanwhile, Eric and Annie are busy getting the house ready for Lucy's surprise baby shower and become concerned when Matt doesn't have her back as planned. Kevin shows Ruthie that he bought a house for Lucy, and Ruthie mentions to Kevin that it will upset Lucy as he didnt consult her first.

In the end, Lucy has a healthy baby girl in which she names Savanah, after the location of Kevin and Lucy's honeymoon.

Eric gains a new perspective on Sandy (Haylie Duff) and Martin's pregnancy when he learns that his own mother was pregnant with him before she married his father. Ruthie has the flu. Eric is also not feeling too good in this episode as Annie wants to take