Grey’s Anatomy is known for dark-and-twisty finales, and tomorrow night’s Season 9 ender is no exception. Not only will it be dark physically — the power goes out after a superstorm hits Seattle — but emotionally, too.

We know a lot about Episode 24: “Perfect Storm," and unfortunately that intel is mostly bad. While there are happy occasions (Meredith giving birth to her son), they come with a slew of problems (delivering via C-section in the dark and the baby not initially crying). At the end of the day, we’re putting our MerDer nervous feelings aside to worry mostly about Calzona. At the end of last week’s penultimate episode, Arizona did the unthinkable, cheating on her wife with hot new doc Lauren, and we’re still in shock.

We’re not just worried about them breaking up — or perhaps even getting divorced, which was hinted at throughout the season — we’re worried about one of their lives’ hanging in the balance. The synopsis says “a doctor fights for their life,” and though Calzona has been through their fair share of trauma, that doesn’t mean they’re safe; on Grey’s, no one is safe.

If you think it seems far fetched, think again. Both Arizona and Callie will be at the front of the line saving lives as the superstorm sends busses flying (one of which sets on fire) and knocks the power out of the NICU, keeping babies from breathing. It’s going to be a mess, and with that comes dangerous situations, and on-edge patients. When things get emotional for Calzona after their “talk,” they could lose focus and make a fatal mistake.

While we’ve already voiced our concerns about Callie’s fate, Arizona has a few other issues at hand — or at leg, rather. She has a higher chance of losing her balance in the rush of things or perhaps even dealing with residual PTSD issues. Plus, as seen at the end of last week’s episode with Alex and Jo, a tree could come crashing in, someone could get electrocuted, or the storm could break windows. Basically, anything can happen, and with Arizona in a heightened emotional state, she’s even more vulnerable.

Do you think Arizona will be OK in the finale, or should we be nervous? Sound off below!

The Season 9 finale of Grey’s Anatomy airs Thursday, May 16, 2013 at 9 p.m. ET/PT on ABC.

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Alyse Whitney is an editor at Wetpaint Entertainment. Follow her on Twitter @AlyseWhitney.