The housewives decides to organize the dinner Mary Alice was organizing; Gabrielle is blackmailed by a 9 year old girl; Bree tries to hide her broken marriage; Karl returns to discuss terms with Susan.
A break-in on Wisteria Lane leaves the neighbors feeling vulnerable; After Rex takes the kids away for the weekend, Bree finds herself bonding with Zach; Gabrielle takes drastic measures to keep Juanita oblivious to her secret.
Lynette locks horns at the twins' school with officious mom Maisy Gibbons; Susan continues to investigate the mystery of Zach's sudden disappearance; Juanita comes closer to discovering Gabrielle's dirty little secret affair.
Susan is miffed when Mike gets an unexpected house guest named Kendra; Andrew gets into a serious car accident that puts Mama Solis in the hospital; Mr. Shaw comes closer to solving who was blackmailing Mary Alice.
Gabrielle decides to organize a glamorous Halston fashion show; Bree and Rex are now at odds with each other on how to punish Andrew; The police investigate the skeletal body in a toy chest that Paul Young dumped in the river, and begin to close in on his secret.
Bree finds out that Rex is cheating, and he has a heart attack; Susan plans to take her relationship with Mike to the next level; Lynette, suspicious of her new nanny Claire, decides to secretly videotape her.
Edie organizes a neighborhood search for Mrs. Huber, just as her sister arrives on Wisteria Lane; Bree agrees to a separation and asks an attractive pharmacist on a date; Susan's ex-husband, Karl, suddenly returns for a visit; Lynette's fears Tom is attracted to their nanny.
The residents of Wisteria Lane learn the fate of Martha Huber; Susan confesses to Edie about her role in her house fire; Bree finds George getting a little too close for comfort; Carlos is released on bail, and placed under house arrest.
Susan looks forward to a romantic date with Mike until she learns a surprising fact; Lynette's neighbor accuses her twins of thievery; Bree learns of Rex's sexual needs; Gabrielle's work adventures continue.
Mike is questioned in Martha's murder; Justin tries to blackmail Gabrielle; Tom wants a big promotion, but Lynette fears she would be left alone with the kids even more; Julie learns of Zack's dark side.
Maisy Gibbons' series of unfortunate events shocks Wisteria Lane; Gabrielle and Carlos' sewer system goes out; Lynette learns of a rumour that her twins started a head lice epidemic; Susan finds a surprising ally after her breakup with Mike.
Mama Solis' awakens from her coma, as Gabrielle and Carlos fret over their financial issues; Lynette befriends a deaf woman; Bree encounters more trouble when disciplining Andrew; Susan finds herself attracted to Edie's hunky new contractor.
Susan's mother pays an unexpected visit; Gabrielle faces Carlos' wrath; While babysitting Lynette's children, Bree punishes the twins for misbehaving; Felicia gets closer to Zach, revealing more disturbing details about his family.
Lynette learns that no good deed goes unpunished when she befriends Mrs. McClusky; Susan's mother decides to try to jump-start her and her daughter's love lives; Bree forces Andrew to talk to the family priest about his conflicted sexuality.
Gabrielle plans a big party to bid farewell to Carlos and begins to suspect she's pregnant; George Williams returns, much to Rex's displeasure; Lynette learns Tom's old girlfriend, has been hired at his firm again; Susan and Julie encounter strange behavior from the Young family.
Susan and Mike decide to move in together; Lynette takes steps to make sure Annabel doesn't come between her and Tom; Bree comes to a realization about George; Carlos' legal problems take a turn for the worse; Martha Huber's journal falls into the hands of Susan and Julie.