It is a holiday weekend on Wisteria Lane. Bree and Orson are going on their honeymoon, while Gabrielle and Lynette are going a spa vacation and Tom is going on a camping trip with the kids. Meanwhile Susan is going on a quiet romantic getaway with Ian, not sure if she's cheating on Mike. However, things don't go as planned.

The residents of Wisteria Lane celebrate their annual holiday block party. Meanwhile, Gabrielle sets her eyes on a father of a girl she's coaching. Mike is arrested for Monique's murder. Thanks to Lynette, mothers of the neighborhood arrange a protest against Art. This causes his sister a heart attack. And Susan has to cook dinner for Ian's parents.

While Tom tries to save his marriage, Mike and Susan get engaged. However, Susan's happiness is short-lived when she realizes Gabrielle has stolen her cancelled wedding with Ian. Meanwhile, Edie wants Carlos to move in with her, and she's ready to do anything to make it happen.

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

"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.

Susan's daughter Julie comes to visit with her surprising new boyfriend. Gabrielle learns that Mrs. Hildebrand has made her and Carlos heirs of her entire fortune. A reporter looks to expose Bree's imperfections. Lynette learns Porter and Anne Schilling plan to leave Fairview and disappear. Finally, everyone has gathered at a club to see the guys play in the annual "Battle of the Bands" when a fire erupts, threatening the lives of those in attendance. Some will fall as a hero will rise.

When Eli Scruggs (Beau Bridges), the neighborhood handyman, passes away, the residents of Wisteria Lane realize how much he affected their lives.

A chance encounter reunites Gaby with her sexy ex-lover and gardener, John Rowland; Bree contemplates a weekend getaway with Karl; Lynette and Tom break the news to their kids that she's pregnant again; and Susan is convinced Angie's son is responsible for her daughter's attack.

Angie’s ex-boyfriend, Patrick, emerges after her trip to New York. Meanwhile it’s game on between Gaby and Susan, as they go to shameless lengths to top each other’s kids; Lynette believes there’s more to Preston’s fiancée than she’s letting on; Bree invites Sam over for a family dinner; and Katherine comes out of the closet.

Lynette comes to a shocking realization about Eddie. Meanwhile, Angie discreetly relies on Gaby for help when Patrick threatens the life of her son; Bree offers Sam a generous payoff to walk away; and Susan and Mike's financial woes result in the ultimate sacrifice.

Paul's nefarious plan for Wisteria Lane is put into full effect. Juanita discovers that she isn't Gabrielle's biological daughter, and Bree invites Keith (guest star Brian Austin Green) to move in with her, whilst Tom is confronted about his past indiscretion with Renee.

The Wisteria Lane residents each enjoy a progressive dinner; Renee begins a short-lived relationship with a bartender; Bree sees a connection with Chuck; the housewives cover up a fatal accident.

While Bree gives Chuck a ride, a smell becomes noticeable; Gabrielle seeks out a priest in order to help Carlos with his problem; Ben Faulkner, a new neighbor, meets Renee; Susan withdraws from her friends because of what happened to Alejandro.

Bree's trial finally comes to an end with a surprise confession. Tom takes steps to finalize his divorce.