The new neighbors, the Applewhites have moved in. Gabrielle, Lynette, and Susan attempt to comfort Bree while Rex's mother arrives on Wisteria Lane for his funeral. Meanwhile Mike and Susan deal with Zach while Gabrielle struggles with the two men in her life.

Susan is surprised when she finds out who Edie's new boyfriend is. Meanwhile, Lynette has gone back to work, leaving Tom at home in charge of the house. Carlos makes an unusual request to Gabrielle after his life is threatened behind bars. Lastly, pharmacist George reemerges in Bree's life, which sets off an alarm to mother-in-law Phyllis and her suspicions surrounding her son's death.

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.

On one of Gabrielle's prison visits to see Carlos she creates a terrible riot, which lands Carlos in hot water. Also, Susan puts her feelings aside and joins Mike in searching for his son Zach. Lynette is surprised to find out that her son Parker has an imaginary friend. Lastly, George and Andrew both vie for Bree's attention as they both compete in making each other look bad in front of her, until one fight goes a little too far.

Susan's longtime book agent and dear friend, Lonny Moon gets into financial trouble. Lynette is forced to go out to bars night after night with her man-hungry boss, Nina. Bree finds out about Rex's feelings about her prior to his death. Lastly, Gabrielle hires hotshot lawyer David Bradley to defend Carlos in court but Carlos rejects him after he witnesses an attraction between David and Gabrielle.

Mike and Susan face a crisis in their relationship when Susan tries to get Paul Young arrested by confessing to a police officer that he killed Mrs. Huber and Mike has her diaries as proof. The officer goes over to Mike to get the story, but Mike denies the whole thing. As Carlos continues serving his jail sentence, Gabrielle valiantly tries to free him. Bree goes to a romantic hotel with George, but requests they sleep in separate rooms.

Gabrielle tries to revisit her past when old friends come to town, but doesn't want anyone to know that she's three months pregnant. With the aftermath of her breakup with Mike, Susan finds temporary solace from her ex-husband Karl as his relationship with Edie hits a bump. Also, the Scavos learn more about the new neighbors, the Harpers when they babysit their children and uncover a sex tape of the couple. Lastly, Caleb gets loose from the basement and roams around Wisteria Lane at night, which leads to major consequences for Gabrielle.

All of Wisteria Lane is panicked by a burglar loose in the neighborhood and thus a neighborhood watch committee is formed. Bree finds out some disturbing information about George. At the wedding of Sophie and Morty, Susan learns who her real father is and is determined to find him.

George stalks Bree, despite her efforts to break up with him. Lynette takes charge of office politics. Carlos is paroled from prison and returns a new man, and Gabrielle is jealous of his new 'holier-than-thou' confidante. Susan meets her birth father and tries to begin a relationship with him.

Lynette tries to put a daycare center in Parcher & Murphy by recruiting employees' children to get the program started. Gabrielle and Sister Mary Bernard face off over Carlos' mission of mercy to Africa. Bree brings Andrew home and tells him about the revelation of George poisoning his father Rex and killing him. Lastly, Susan confronts her biological father's wife after she thinks they are having an affair.

Gabrielle kisses Tom and Lynette is not happy and drives a wedge in her friendship with Gabrielle. Paul attacks Mike. The housewives become more suspicious of Betty and her family. Andrew is trying to blackmail Bree, but Bree gets some assistance from Susan's ex, Karl.

After a number of bad dates, Susan finally meets Dr. Right. Susan flirts with a handsome doctor, but they accidentally head butt. Meanwhile, some old pictures of Gabrielle turn up on the Internet. Tom is alarmed when his kids come down with chicken pox because he never had it. Bree gets arrested. Lastly, after months of silence, Noah Taylor contacts Mike Delfino.

Dr. Ron informs Susan that she needs a splenectomy. Gabrielle and her arch-enemy Sister Mary Bernard finally face off in church.

Also, Tom decides to apply for an empty position at Lynette's job, which leads to the arousal of past issues in their marriage. Lastly, Matthew and Danielle's relationship is found out by both their mothers, which leads to big repercussions later on for Bree and her past secret with Andrew last year.

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.

Edie thinks that Karl is going to pop the question after she finds an engagement ring and prenuptial agreement in his briefcase. Also, Gabrielle and Carlos learn she is highly unable to conceive a child again because of complications caused from her recent miscarriage. Lastly, Bree's problem with alcohol intensifies with the notice of Lynette after Bree babysits her children.

Carlos and Gabrielle decide to adopt, but the process comes to be a lot more difficult than either had expected. Susan finally has her surgery as she finally has medical insurance. Meanwhile, a showdown between Bree and her son Andrew lead to a full out war between mother and son. Also, a dying Noah Taylor learns more about Paul Young and his biological grandson Zach. Lastly, Tom is having more difficulty at the job when having to take orders from his boss and wife Lynette.

Susan invites Dr. Ron to meet Karl after he finds out about their arranged marriage. Lynette is surprised that a woman at work is still breastfeeding her child of five. Gabrielle becomes very picky when choosing a birth mother, and a beautiful baby. Bree has to deal with a fresh accusation from Andrew, that of repressed memories.

Carlos and Gaby learn the truth about their baby. An ex-stripper gives birth to her child, and Gabrielle holds her for the first time. Also, Paul Young comes to face his demons head on with Wisteria Lane. Lastly, Lynette is forced to give a court deposition about Bree's drinking and alcoholism.

Lynette is called in to her kids' school as Parker has gone from being obsessed with Dinosaurs to being obsessed with nudity. Carlos and Gabrielle must go to court to get custody of their baby. Bree's father Henry and stepmother Eleanor come to town to mediate between Andrew and her. Susan is convinced that Karl doesn't really love Edie. Later, she goes to a movie theater, and spots Mike with a date.

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.

Bree and Andrew finally reach an impasse in their relationship as tension has finally reached a critical point. Meanwhile, Ed finally fires Tom with the pressure from his wife. Lastly, Edie's private detective begins to uncover numerous details of Karl and Susan's relationship as of recently. Gabrielle is having a tough time keeping her servant in the country.

Reaching the end of her rope, Bree checks herself into the Fairview psychiatric hospital. Lynette suspects that Tom is cheating on her, so she follows him to Atlantic City. Susan must start over. Felicia Tilman has more in store for Paul Young, resulting in their war reaching its final battle. Gaby and Carlos get Xiao-Mei pregnant.

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.

Susan learns that she is expecting a child while Bree continues to fake her own pregnancy. Gabrielle begins an affair with her ex-husband, Carlos and Lynette tries to conceal her cancer from her friends and children. The episode also introduces Katherine Mayfair, Susan's old friend who returns to the neighborhood after being away for 12 years.

Lynette kicks Tom out of her chemotherapy sessions. Susan is mistaken for a stripper. Bree attempts to steal a prize-winning recipe from Katherine.

Bree informs the housewives of what she overheard in the Mayfair house. Stella makes some special brownies to help Lynette through chemotherapy. Susan throws a charades party for the whole neighborhood.

Edie is shocked when she receives some news at the gynecologist's office. At the baby shower Bree's friends throw her, Bree's ex-mother-in-law Phyllis discovers her pregnancy is a hoax. Finally, Wisteria Lane welcomes to the street a homosexual couple.

Bob & Lee's contemporary water sculpture in their front yard prompts the Wisteria Lane neighborhood association into action. Edie finds out about the affair that Carlos is having with Gaby. Also, John Rowland wants to rekindle his romance with Gaby.

This is the show's first Halloween episode. Edie Britt's biggest fear comes true when Carlos walks out on their relationship. Susan finds Mike's father, who was supposedly dead. Danielle goes into labor right in the middle of the Halloween party... and somebody has to deliver the baby.

Lynette's sisters Lydia and Lucy come to visit. While having dinner with Susan and Mike, Bree and Orson realize they share different views on whether their newborn baby should be circumcised. On a boat, Victor confronts Gaby about her affair with Carlos and she throws him into the ocean. Later, Bree informs Susan that she thinks Mike is addicted to drugs.

A mysterious stalker from Adam's past shows up on Wisteria Lane, and they have dinner. Detectives question Gabrielle about Victor's whereabouts. Danielle's baby puts stress on Bree and Orson's marriage. Lynette has a reunion with her long-lost stepfather, Glen. Susan notices Mike is behaving strangely.

A tornado comes to Wisteria Lane, forcing residents into basements, cellars and safe rooms, and destroying homes and lives. Meanwhile, Susan ends up at the hospital after falling down the stairs.

In the aftermath of the tornado, the residents of Wisteria Lane try to rebuild their lives. Katherine discovers someone may know her secret while Lynette faces the possibility of her family's fate.

Two weeks after the tornado, with Mike still in rehab, Mrs. Delfino gets a visit from her cousin Tim. Meanwhile, Bree desperately awaits to return to her own house. Gabrielle learns that Carlos' blindness is permanent. Katherine is unable to keep some of her secrets from the women of Wisteria Lane. Finally, a surprise wedding ceremony has its own share of secrets.

Gabrielle struggles with the reality of having a blind husband. Lynette is surprised when Rick Coletti shows up at the Scavo pizzeria. Bree and Katherine join forces to plan the Founders Day Ball. As part of his recovery, Mike asks a few people for forgiveness, and Orson starts sleepwalking.

Bree and Katherine decide to start a catering business together. Lynette tries to deny her feelings for Rick. Mike learns the truth about his nearly fatal accident. Carlos gets a seeing-eye dog. Dylan meets her estranged father.

Susan meets her ex-husband, Karl at a Lamaze class, and finds out that he has remarried and is having another child. Lynette learns who was responsible for starting the fire at Rick's restaurant. Bree wants Orson to turn himself in to the police. Meanwhile, Gabrielle rents a room to a hip artist, Ellie, who has a dark secret. Elsewhere, Dylan continues meeting with her father, Wayne, and Katherine decides to go spy on her.

Adele Delfino, Susan's mother-in-law, arrives for a visit. Carlos and Gabrielle find out their tenant, Elli, has a dark secret. A full scale war erupts between Bree and Edie.

"The Gun Song" is the 86th episode of the ABC television series, Desperate Housewives. It is the sixteenth episode of the show's fourth season, and the first half of the two-hour season finale. It aired on May 18, 2008 in the United States.

Susan and Mike try to name their son. Lynette is arrested for supposedly attacking Kayla, and Tom must do what he can to save his family. Bree is being stalked by Orson, and when she meets with Reverend Green, the reverend tries to hit on her. In the meantime, Gabrielle is still helping the police trying to detain Ellie for dealing drugs. Finally, Katherine is visited by her ex-husband, Wayne.