Episode 23 of "Desperate Housewives"
s01e23 One Wonderful Day

Gabrielle, Susan, and Lynette rush to the hospital in the middle of the night after recieving a phone call from Danielle telling them about Rex's heart attack. 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. Before his operation, Rex apologizes for being a bad husband. After not getting any better, the doctor suggests to Rex that maybe Bree was tampering with his mediction. Rex writes her a note telling her that he understands, and then dies not knowing the real truth. Minutes later, a doctor calls Bree to tell her that Rex has died. She numbly sits in her empty dining room, looking at the chair where Rex would normally sit. She goes into typical Bree coping mode by polishing the silver but then she dissolves into heartbroken sobs. Lynette's marriage takes a dramatic turn after an upset Tom, who accidentally quit his job under false pretenses due to Lynette's manipulation, vows that it is now her turn to go back to work and he'll be staying home with the kids. And Lynette may just take his offer. 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. After realizing it's about Dierdre, Paul reveals why Mary Alice killed herself: a drugged-out Dierdre sold them her baby to feed her habit. They fled Utah and changed their names, but she still found them. Mary Alice killed Dierdre by accident when she came to forcibly take Zach/Dana back from them and they hid her body where they thought it would never be found -- in a toy chest buried under their new pool. In the end Mike doesn't kill Paul, but goes home where Zach is waiting for him, while pointing a gun at Susan.