The streets of Glenoak are alive with the sound of music as the Camden family breaks into song for a very special Valentine's Day musical episode. Classic songs (""Love Is Sweeping the Country,"" ""You Were Meant For Me,"" ""Nice Work If You Can Get It,"" among others) are performed by the Camdens. Simon is enjoying having his new girlfriend, Anna, who he just met the day before over at his apartment for Valentine's Day. They both agree to go to Glen Oak, but he decides to keep her away from his family for the time being. Annie displays her unhappiness to Simon in song (along with the rest of passerbys) over his constant dating habits at the promenade as the chorus is going on. Anna overhears this and begins to question Simon and his dating habits as well. Vincent confronts an unhappy Ruthie on the high school bleachers as she's not in the Valentine's Day mood and is upset over watching Martin practice with his team and Zoe blowing kisses at him. Also, Lucy and Kevin dance to ""You Were Meant

After Eric agrees to take in a French exchange student (Guy) as a temporary border, no one but Ruthie suspects the young man is actually a con artist. Suave and romantic, the border attracts both Mary and Lucy after he flirts with them. Simon and Ruthie get sick when they try to smoke Guy's cigarettes. Also, Guy steals Matt's date. Lastly, Eric and Annie discover e-mail and chat-rooms on Guy's laptop computer and begin a romance with each other over the internet.

The Camdens, especially Lucy and Ruthie, grow concerned that an unusually joyful Annie isn't dealing with her true emotions following the death of her father Charles, but the happiness proves to be infectious as it soon spreads through the family and all over town. Meanwhile, Eric tries to convince an unhappy Chandler that he should consider adoption. At the same time Chandler is approached by a mysterious young girl who gives him a cryptic message before she disappears.

Simon and Rose prepare for their wedding day, despite speculation that it is not the right decision. Annie and Eric go through countless scenarios in their minds as they reflect on how the wedding will actually turn out.Meanwhile, Rose's former boyfriend shows up unexpectedly. Ruthie considers studying in Scotland over the summer. Kevin, Lucy, Matt, and Sarah all have life-changing news, if only they can find the perfect time to share it with the family...and the surprises don't stop there!

Lucy and Kevin celebrate their one-year wedding anniversary and contemplate whether they're ready to start a family, but things don't go off smoothly as Lucy refuses to drink champagne with Kevin during their anniversary dinner. Cecilia and Martin realize that their relationship may face a rocky future if Cecilia goes away to college. Chandler's foster son asks him to rid their house of all alcoholic beverages. Peter lies to Ruthie about his plans for the evening when she asks him to help her baby-sit the twins. With that, Peter goes missing, but concern turns to disappointment when Eric and Vic find him drinking alcohol with his friends at the park.

As election day approcahes, Ruthie is on a mission to develop her own opinions about politics after seeing how much Martin knows about world politics. Meanwhile, both Eric and Annie are suspicious that the other did not vote in the last election. Also, Lucy is feeling the pressure of registering to vote and is surprised to learn that Kevin hasn't changed his address and therefore isn't registered either. Eric is having a hard time teaching the twins that politics are not stupid. Lastly, the family gets a nice call from Carlos and baby Charles.

Racism comes to light at the high school when Alex, a new African-American student, wants to give a report on Dr. Martin Luther King, but his teacher argues that they have already covered that topic in class. When Martin inadvertently supports Alex's case, he falls victim to a hate crime. His car is defaced with racial slurs, and he refuses to wash it off until the culprit is caught. Meanwhile, for her own report, Ruthie attempts to recycle an essay that she wrote three years ago.

Eric tries to help Chandler after the young minister learns that his father is dying of lung cancer, but Chandler rejects Eric's aid and pushes him away. Lucy accepts a date with Chandler's chain-smoking tattooed brother Sid in order to make Kevin jealous enough to propose to her. Elsewhere, Annie is shocked when she finds a pack of cigarettes in Simon's bedroom. Lastly, Ruthie's friend Peter begs her to lie and not tell his mother that he smokes.

Annie's half-sister Lily shows up on her doorstep to discuss an important family matter after Annie refused to contact her. Eric tries to figure out why Annie won't contact Lily. Meanwhile, Cecilia sets Martin's friend Mac up with a girl from school, but he doesn't want to go out with her because of something embarrassing that happened ten years ago; Ruthie and Peter put a bad spin on a school project that lands them in trouble when they create a newspaper featuring false and derogatory stories about two former US presidents. Lastly, Roxanne turns to Chandler when she finds herself faced with a moral dilemma as she is keeping a secret from Kevin regarding Detective Michaels.

When Kevin leads Venus (guest-star Martha Plimpton), a young woman, to believe that Martin is a rookie cop, she quickly expresses interest in him. Martin's friend Mac (guest-star Kyle Searles) encourages him to pursue Venus. Martin has a hard time revealing the truth after he learns that Venus' father is serving in the Middle East. Meanwhile, Eric and Annie are worried that Martin is getting in over his head with Venus and enlist Kevin to fix things, which only leads to rumors around the police station that Kevin is cheating on Lucy. Mac also jumps in by spreading rumors about Martin at school. Lastly, Ben (guest-star Geoff Stults) continues to hide his relationship with Lucy's new baby doctor, even though they spend a weekend together.

Although he practices safe sex, Simon panics when his girlfriend of the moment, Sandra (guest-star Olivia Allen), confesses to him that she has an STD. Meanwhile, Martin and Mac (guest-star Kyle Searles) catch Ruthie's boyfriend, Vincent (guest-star Thomas Dekker), on a date with another girl. Also, Matt, Lucy, Kevin and Ruthie have second thoughts about telling Eric and Annie that Mary (Jessica Biel, who does not appear in the episode) is pregnant again, but also to hide the fact that she has deserted her husband Carlos and her baby son Charles. Lastly, Annie decides to go to New York to pay Mary a visit.

Annie and Ruthie spend the day together to unwind, while Lucy's world becomes complicated by both professional and personal news, and Eric unintentionally shakes up things between Rose and Simon.

Eric Camden finds himself on a hung jury of a case that he considers ""open and shut,"" only to realize that he must help the other jurors regain their faith in the legal process in order to reach a fair verdict. Meanwhile, the other Camden's are suffering their own wrong doings as Annie and Ruthie ponder whether two wrongs make a right. Mary becomes in debt with Lucy after accidently giving her a black eye. Also, Simon and Deena realize that saying ""sorry"" can't turn back time, and Matt learns how important one person's voice can be.

Mary tries to right a wrong by explaining to Lucy that she never had adult relations with her sister's fiance. The only problem left is trying to convince Lucy. Wilson unexpectedly drops by the Camden home from New York to see if he and Mary are really over by finding out her answer. James talks to Eric about him attempting to have an affair with Annie as Serena comes clean with Annie about her trying to have an affair with Eric. Robbie and Wilson set aside their differences so that they can talk about Mary. Matt learns a few things when it comes to Cheryl's honesty when she doesn't tell her friends that she's dating him.

Eric and Rabbi Glass pay a visit to the church to spy on the new associate pastor. Meanwhile, Ruthie is in big trouble when she's caught slow dancing with her boyfriend when she's supposed to be babysitting Sam and David. Meanwhile, Lucy asks Simon to dig up some information on Roxanne during his ride-along with her and Kevin in their patrol car. Lastly, Kevin has some explaining to do to Lucy after he runs into his ex-wife.

Eric arranges for Peter and his dog to visit a drug rehab center to cheer up the patients. Peter bonds with Nick and helps him reconnect with his estranged son. Lucy finds out that Kevin has been secretly coaching the Glenoak Police Department husband-and-wife softball team and demands that she be allowed to play. Just before his first date with Paris, Chandler receives a letter from Roxanne telling him she still loves him. Martin confronts Cecilia about her lingering feelings for Simon, prompting Ceclia to call Simon to let him know she has a new boyfriend. She is also surprised when he admits that he is also dating someone and Ruthie is jealous of Cecilia and Annie's close relationship.

On a temporary leave from military duty in Iraq, Martin's father pays the Camdens a visit to help his son decide whether to forgo college for a career in professional baseball. However, the visit turns sour when Martin catches his father kissing Roxanne. Meanwhile, Chandler and Paris reevaluate their relationship in the wake of her ex-husband's return, and Roxanne comes to blows with Martin's aunt over their differing views on the war in Iraq. Lastly, Vic tries to join the Marines and talks to a supervisor over the matter.

Annie's half-sister Lilly is getting married and wants their ailing father to walk her down the aisle but Annie worries that the strain might be too much for him. Meanwhile, Fred and Mrs. Bink attend premarital counseling with Chandler, but Fred's mother tries to put a stop to the wedding because she thinks Mrs. Bink is a gold digger. Lastly, Jimmy and Pat, two mentally challenged people, decide to get married after just one date and ask Chandler to perform the ceremony, but Jimmy's parents try to put a stop to it.

Ruthie is on cloud nine when an emotional Eric and Annie reluctantly agree to let her go on her first official date. However, Ruthie isn't surprised to find the family handling her big news with their usual crazy Camden ways: Annie and Lucy decide it's their job to help Ruthie prepare for her date with Vincent (guest star Thomas Dekker); Kevin takes it upon himself to give Ruthie ""the talk""; Sam and David change into their Sunday best so they can go on the date as well; an overprotective Martin and Mac (guest star Kyle Searles) decide to spy on Ruthie and Vincent's date; and Matt volunteers to play chaperone, but finds himself in a web of lies to protect Ruthie's feelings.

After discovering that Mary (Jessica Biel, who does not appear in the episode) has filed for divorce and signed away custody of her son, Matt is at a loss for how he should to break the awful news to Eric and Annie. Simon informs his new girlfriend, Rose (guest-star Sarah Thompson), that he won't have sex with her, but avoids telling her the reason behind his decision. She gets fed up with him but comes back to him when she finds out his true intentions for them---marriage. Meanwhile, Ruthie's boyfriend, Vincent (guest-star Thomas Dekker), asks Martin to get Ruthie to break up with him. Also, Eric gets involved once again with the Davis family children when little boy Danny (guest-star Drake Johnston) is being adopted by Cecilia's parents, George and Gwen (guest-star Brad Maule and Holly Fulger), but forgets to mention that the kid is part of a package deal as Danny has three sisters in Social Services as well, and try to take them in as well. Kevin is about fed up with Lucy as he's fr

When Simon and his new girlfriend Rose (guest-star Sarah Thompson), make an unexpected visit to Glenoak to meet their respective parents, Annie begins to suspect their relationship might be on a fast track. She let's them know they are not allowed to sleep in the same room together in the house as they spend the night. Rose puts up a fight with both Annie and Simon over the sleeping arrangements, but eventually take will. Meanwhile, Eric hides the news of Mary's (Jessica Biel, who does not appear in the episode) divorce, worried that it will most certainly break Annie's heart. Also, Martin becomes the third wheel again in Ruthie and Vincent's relationship as Ruthie thinks Martin is jealous of their relationship despite the fact that Vincent wants Martin to convince Ruthie to dump him. The adoption process for George (guest-star Brad Maule) and his wife over the Davis children becomes more complicated when their biological mother fights for the adoption process to not happen. Lastly, Ma

Eric meets Sandy's father, who gives him an envelope of money intended for Sandy; and Ruthie collects soup-can labels to help her school's newspaper. Elsewhere, Simon has money troubles and his phone service gets shut off; and Martin has a heart-to-heart talk with Meredith about their future. Sandy: Haylie Duff. Meredith: Megan Henning. Edward: Michael McDonald. Beau: Costas Mandylor.

When Sandy's (Haylie Duff) father (guest star Michael McDonald) approaches Eric and Lucy with plans of helping his daughter, they are suspicious of the large sum of money he leaves with them. Meanwhile, Martin decides it's time to confront his father (gue

When Ruthie and T-Bone work on a school assignment about the genocide in Darfur, they get the whole Camden family, and the community involved in the cause.

Ruthie tries to hide her tattoo from her parents, not realizing that they already know something's up with her. Lucy knows about the tattoo, but she has a very specific reason for keeping it to herself. As it turns out, most of the Camdens have dirty little secrets that they'd rather not reveal...