Cash-strapped Mrs. Huber figures out that Susan had something to do with Edie's house fire and tries to blackmail her. Meanwhile, Carlos becomes suspicious that Gabrielle is seeing another man, but targets the wrong suspect---the cable guy instead of gardener John. Also, Lynette balks when the twins' teacher insists the boys have ADD but tries to salvage the matter by seprating the boys. Lastly, Bree struggles with her rebellious son Andrew after Rex moves out.

It's Valentine's Day on Wisteria Lane, and love is all around (sort of), as Susan looks forward to a romantic date with Mike, until she learns a surprising fact about her favorite plumber. Meanwhile, after reconciling their relationship, Bree discovers something new about her husband Rex when it comes to his sexual needs. Lynette's neighbor accuses the Scavo twins of thievery as Lynette tries her best to handle the situation. Lastly, Gabrielle's work adventures continue as she gets a gig as a mattress model.

Mike Delfino is questioned about Mrs. Huber's murder by police and is arrested. John's friend, Justin attempts to blackmail Gabrielle with his knowledge of their affair. Meanwhile, Tom wants a big promotion, but Lynette fears that she'd be home alone with the kids more than ever and tries her best in discouraging him in taking the job. Also, Bree is shocked when she finds a condom. Zach Young plans a pool party for the teens on Wisteria Lane, and things get out of hand. Finally, someone comes out of the closet.

Bree confides that she feels guilty because she and Rex were having a fight when he had his heart attack and that now he needs a pacemaker. Lynette's marriage takes a dramatic turn after an upset Tom vows that it is now her turn to go back to work and he'll be staying home with the kids. Carlos finally learns that John and Gabrielle have been lovers for a while, and vows revenge as he is carted off to jail. Mike takes Paul out to a deserted quarry, intending to shoot him.

Susan tries bravely to accept Edie’s new role in Julie’s life, while Lynette’s demanding boss makes her miss Parker’s first day of kindergarten. Bree later on takes a polygraph test to prove her innocence in Rex's death and realizes she has feelings for George.

Gabrielle finally comes to the truth about Carlos and John after seeing John with another woman.

Tom tries hard to bond with his new boss and tries to get Lynette to help him out. Meanwhile, Susan gets some help from Edie and Karl on her situation of getting health insurance before her upcoming surgery. Gabrielle becomes very attached to a temporary Chinese immigrant housekeeper who is staying with Solis' after being rescued by another slave owner employer. Lastly, Bree tries to uncover more about the Applewhites by sneaking into their house to meet Caleb.

Gabrielle and Carlos are shocked when the father of their baby shows up to take the baby back. Cops and a lawyer arrive to a house on Wisteria Lane. Lynette tries to help Ed heat up his sex life. Meanwhile, Karl decides to break up with Edie, as Edie has no idea that Susan is the "other woman." Edie causes a fight to break out in a bar, after she trips a waitress. Lastly, Bree is taken a step forward to help Peter when she finds out how bad his other addiction is.

Flashbacks take us back to to moving-in day on Wisteria Lane for Bree, Lynette, Susan and Gabrielle and how Mary Alice brought them all together. Back in the present, Bree gets some frightening news. Susan moves into a trailer after her house was burnt down. Lynette and the kids are staying at a hotel. After seeing a report on the news, Gabrielle believes Carlos died. Paul begs Zach to get him a good lawyer via Noah.