It wasn’t much of a surprise last week on General Hospital when Heather announced that Elizabeth and Hayden are sisters. The clues had been building for a while, but when we first got the inkling that’s where GH was going, we were shocked.

Apparently, plans to make these mortal enemies sisters had been brewing for a while, mainly so Hayden had more of a tie to Port Charles than just the con woman Rick (Rick Hearst) hired to be “Jake Doe’s” wife, later revealed as Rachel, the daughter of con man Raymond Berlin.

According to the September 19 issue of Soap Opera Digest, the Rachel reveal was only a small part of the ultimate plan.

“We decided fairly early on to ground Hayden more firmly to the canvas by making her Elizabeth’s sister,” Head Writers Jean Passanante and Shelly Altman told Digest.

They added that “a sibling bond is a classic setup for story [and] so is a sibling rivalry.”

We knew there had to be some reason these two passionately hated each other aside from Hayden’s initially trying to steal Jake/Jason from Liz–just for a few bucks. When Hayden (Rebecca Budig) learned that Liz (Rebecca Herbst) was an accomplice to Nikolas (Tyler Christopher) having her shot, that just solidified their hatred for one another.

That leaves at least one missing element here–their long-MIA shared father. A casting call this week set off rumors that GH would bring back Jeff Webber as Hayden and Elizabeth’s dear old dad, and it looks like the writers aren’t ruling that out.

When the topic came up, they said: “That would be great, wouldn’t it.”

See what’s coming up next!