[Warning: This post contains spoilers from Episode 3 of Law & Order: SVU, titled "Contrapasso." Read at your own risk.]

Brooke Shields finally made her explosive debut on Law & Order: Special Victims Unit with a jaw-dropping reveal that promises to turn Olivia Benson's (Mariska Hargitay) world upside down. Wednesday night's episode saw her showing up on the SVU sergeant's doorstep to reveal herself as Sheila Porter, Noah's biological grandmother.

"There was something about meeting at a door where the door is opened and we're both shocked by what we see. We don't know the other person at all and the one common denominator is Noah. So that means all bets are off," Shields tells TV Guide of that first meeting. Shields and Hargitay might be friends in real life -- Hargitay is the one who suggested her for the role -- but there won't be any love lost when they go head-to-head on the series.

Benson adopted Noah as her son after his biological mother Ellie (Emma Greenwell) was murdered by her former boss last season. With Ellie lying about not having any living relatives, Benson had no way of predicting that a stranger would show up to claim her son. Her brief but tense encounter with Sheila kicks off a serious battle that, according to Shields, is about something more than simply winning.

"There's something much bigger and this is not about ego...it's just about the power of being a mother," she added.

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Her character brings extra strife into Benson's already tumultuous life which probably won't sit well with fans. Shields, however, says she's prepared for the backlash.

"I've grown up with backlash. I usually get backlash for the breath that I take. So that will not be a new thing. But what I think fans will understand is that both of these women actually have a valid argument," she explained.

While both characters are expected to butt heads this season, everyone can take comfort in knowing that Sheila has no intention of taking Benson's place. "I'm not there to replace her. I'm not there to undermine her or stamp her out so I'm not an adversary in that way."

Law & Order: SVU airs Wednesdays at 9/8c. on NBC.

Mariska Hargitay, Law & Order: Special Victims UnitMariska Hargitay, Law & Order: Special Victims Unit