The season finale of Desperate Housewives will surely leave many unanswered questions (Will Andrew start sleeping with Zach? How much farther apart will Teri Hatcher‘s thighs get?), but that doesn’t matter when the gaggle at Datalounge put all the plot pieces together for us. Mary-Alice mystery solved.
We think Mary-Alice (in her old life and under her previous identity) stole a baby boy — named “Dana” and re-named Zach — from the hospital where she worked as a nurse (alongside Mrs. Huber’s sister, Felicia). The baby belonged to Mike’s late wife.
Mary-Alice, Paul (resorting to extreme damage control) and new baby Dana/Zach moved to Wisteria Lane, where they thought they could start new lives. But Mike’s wife found out who took her baby and came to Wisteria Lane to get him back (hence Paul’s cryptic “she was going to take you away” comment to Zach about the dismembered woman in the toy chest). Paul killed the wife (again, drastic damage control), and the memory of Dana in the process, and buried the body in the toy chest under the pool…likely without Mary-Alice ever finding out.
All was well until 2004, when someone from their past sent Mary-Alice the “I know what you did” note (referring to the kidnapping or the killing or both), which may or may not have led to Paul revealing his murder, but nonetheless prompting her suicide as a result of guilt, shame and panic.
Felicia Huber, in her chat with Zach, told him that they “met” before, and that she remembered his beautiful name, “Dana.” She’s probably put the pieces of the puzzle together by now, as far as Zach being the stolen baby from years-gone-by is concerned, but we’re not sure whether she knows Mike may be Zach’s real father.
In summary: Mary-Alice killed herself because Zach is a stolen baby, whose mother was murdered by Paul and whose father may be Mike Delfino.