As far as prime-time whodunits go, the demise of Desperate Housewives’ Edie Britt on April 19 isn’t much of a mystery. Nicollette Sheridan, who has played Wisteria Lane’s naughtiest neighbor for the past five seasons, knows exactly who did her in.

“Somebody up there really wanted her dead,” says the 45-year-old actress, referring not to the heavens, but to an even more powerful place—the office of Housewives creator Marc Cherry. Now she’s just trying to figure out the whydunit.

“I think that whoever Edie represented in Marc’s life was somebody he didn’t like,” says Sheridan. “And he had a very difficult time distinguishing between fact and fiction.”

Although Cherry was always careful to distinguish Sheridan as a supporting player to his leading foursome (Teri Hatcher, Marcia Cross, Felicity Huffman and Eva Longoria Parker), he consistently served her tragic character an extra helping of desperation. Edie’s had her house burned to the ground. She’s been stung by a swarm of bees. She nearly hanged herself in a botched suicide charade. She was run over by Susan and had to spend weeks in a cast. And she jumped around from househusband to househusband like a blowup doll at a bachelor party. Still, Edie never seemed in real jeopardy until the final moments of the March 22 episode when she narrowly escaped strangulation at the hands of her psychotic husband, Dave, only to crash her car into an electrical pole. The last we saw of poor Edie, she was lying unconscious on Wisteria Lane.

Sheridan couldn’t have been completely surprised by Edie’s demise. During her five years on Housewives, her face was never added to the opening credits. Over time, the actress grew increasingly confused and hurt that Edie was relegated to the back burner and felt Cherry rarely spoke of her in interviews. “When you have a jewel,” she asks, “why not polish it and put it out there for all to see?”

According to Cherry, that shimmering jewel was growing expensive to maintain. Two years ago, he considered killing off Edie when all the actresses’ salaries began to climb. He remembers telling his writers at the time, “If we threaten one of the characters’ lives, maybe they’ll back off.”

But Sheridan was spared and had reportedly approached the other Housewives about renegotiating their salaries in tandem when the series entered Seasons 8 and 9.

That was never going to happen. “There has been tremendous pressure put on me to find ways to cut costs,” says Cherry. “The network is saying to all the shows: ‘The company is really hurting financially. You must find a way to produce these shows more cheaply.’”

Knowing a major character had to go, Cherry had to decide, “What characters do I need to go forward? Edie’s already slept with most of the guys on the street and has caused about as many problems as she could.”

Desperate Housewives, Sundays, 9/8c, ABC; also online at abc.com and iTunes ($)

For the complete story about Nicollette Sheridan's departure, pick up the April 20 issue of TV Guide Magazine!

NEXT: Each Housewive shares their favorite memories of Sheridan.