Wisteria is shocked after hearing the news about Edie. Meanwhile, Lynette undergoes chemotherapy and must cope with its side-effects and a new family moves into the neighborhood.

Lynette, stressed while battling cancer, kicks Tom out of her chemotherapy sessions. Meanwhile, Susan is mistaken for a stripper and Bree tries to steal a recipe.

Bree tells the housewives what she overheard at the Mayfair's house. Meanwhile, Stella makes some special brownies for Lynette to help her through her chemotherapy and Susan throws a charades party.

Edie receives shocking news at the gynecologist's office; a visitor learns the truth behind Bree's 'pregnancy'; and Wisteria Lane welcomes a new couple to the neighborhood who happen to be male partners.

Bob and Lee's water fountain sculpture in their front yard sparks a debate among Wisteria Lane residents. Meanwhile, Edie learns about Carlos and Gaby's affair just as John Rowland returns, hoping to rekindle his affair with Gabriel.

In the sixth episode of the season 4(s4e6), Edie is in real trouble. Her relationship with Carlos is on the rocks. Her worst nightmare comes true when Carlos ditches her and walks out of their relationship. Susan, meanwhile, finds Mike’s father who is presumed dead. An unexpected thing is delivered at the Halloween party, and that leaves everybody surprised and gasping. They try to see what is in the delivery.

In the seventh episode of the season 4(s4e7), things get messy for Gabrielle again. Victor is on Gaby’s case, and comes to know about her affair with Carlos. He confronts her with that. Gaby cannot wriggle out of that. Bree starts a rumor and spreads it. She tells Susan that Mike might be a drug addict. Wisteria Lane gets a new Hodge when he becomes a neighbor.

In the eighth episode of the season 4(s4e8), to the dismay and shock to Adam, a mysterious person springs from Adam’s past and arrives on the neighborhood of Wisteria Lane. The marriage of Bree and Orson and their relationship is on the rocks when the new baby comes into their lives. Lynette suffers from chemotherapy and tries to reunite with her step father.

The residents of Wisteria Lane are forced into basements, cellars and safe rooms to weather a tornado that destroys homes and lives forever.

In the 10 episode of the season 4(s4e10), scenes of destruction that the tornado wrought are shown. It is a depressing picture what with people losing their loved ones and their belongings. With Mrs. McCluskey's house destroyed, Lynette fears and worries about her life and her family. Katherine is in shock when something mysterious from her past comes up. The residents begin the rebuilding.

While Kathryn has trouble keeping her deep secrets from the women onf Wisteria, Susan's attractive male cousin reveals more than Susan bargained for. Meanwhile, a surprise wedding takes place.

In the twelfth episode of the season 4(s4e12), past returns to haunt Lynette. She is shocked beyond measure when someone from her past reappears and gives her chills. Gabrielle struggles to live with her blind husband and knows not what to do. Plans are in full swing for the annual Founders' Day Ball. Bree and Katherine take active part in the preparations.

Bree and Katherine decide to dive into a business venture together. Meanwhile, as Lynette must deny her feelings for another man, Mike uncovers the truth behind his nearly fatal accident.

In the fourteenth episode of the season 4(s4e14), detective work unearths some damning facts about people. Rick’s restaurant was burnt down long back. There were no clues about who did it. But now Lynette comes to know who started the destructive fire. She is shocked by what went behind the scenes then. Susan and Karl come together again. Meanwhile, Bree tells Orson to shape up or ship out.

In the fifteenth episode of the season 4(s4e15), events in some families and relationships between some people come to a head. Families live with past and its consequences. Adele Delfino, Susan’s mother-in-law, comes to visit Susan. Gabrielle and Carlos learn what Ellie, their tenant, is hiding. An ultimate dogfight breaks out between Edie and Bree. Nobody comes out as a winner.

The women of Wisteria join together to welcome Susan and Mike's new baby into the world. Meanwhile, Gaby strikes up a friendship with her tenant, Ellie; and Lynette is accused of child abuse.

The residents of Wisteria Lane are faced with deadly threats; Susan fears she may lose someone she loves; and Katherine Mayfair's dark secrets are revealed.