"Grey's Anatomy" is sending Grey Sloan docs into a maximum security prison in the Season 13 midseason premiere. But no, we're not talking about Dr. Alex Karev (Justin Chambers) and his big cliffhanger decision from the winter finale. Instead, Dr. Arizona Robbins leads a small group into the slammer on official business, and actress Jessica Capshaw revealed that the table read alone left the stars "terrified."

"Arizona's been called in on a case at a maximum security prison for an inmate who can't go to a regular hospital because she's that dangerous," Capshaw told TV Guide.

But it's not just Arizona going; she enlists Bailey (Chandra Wilson) and Jo (Camilla Luddington) for help. "After the longest day of all of their lives, they all go to a maximum security prison, where they are meant to do something that seems like a pretty simple procedure. It's truly kind of creepy at the same time as it's super-provocative and exciting."

Interesting. Whatever happens in prison will surely remind everyone of Alex's dilemma -- Plea Deal Prison vs. Trial Reveals Jo's Past -- and we're definitely curious to see how that is resolved.

Season 13 returns Thursday, January 19, 2017, picking up right after the events of the November 17, 2016 Episode 9.

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