Grey's Anatomy: What or Who Will Be Sacrificed with Jackson in Charge?

When Grey's Anatomyreturns Thursday (9/8c on ABC), there will be plenty of changes going down at Seattle Grace. First and foremost, Jackson (Jesse Williams), who was only promoted to attending this season to fill the void left by Mark Sloan (Eric Dane), is now actually in charge of the whole hospital.

"Holy sh--," Williams tells TVGuide.com from the set of the ABC medical drama. He's not the only one who had that reaction. In the closing moments of the Feb. 21 episode, Catherine Avery (Debbie Allen) announced that the Harper Avery Foundation would help fund Seattle Grace as long as Jackson was the head of the board, something that definitely shocked Jackson and the rest of the newly formed board.

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"Some of it is, 'Mom, how dare you spring this on me in front of everybody without consulting me at all?' But it's also a really daunting task. It's a lot of responsibility," Williams continues and adds that part of Jackson will secretly be flattered. "That's the only thing that keeps him from being totally furious about it; it's somebody believing he can do it."

But the rest of the hospital won't exactly be happy with the new hierarchy, especially Derek (Patrick Dempsey), Callie (Sara Ramirez), Arizona (Jessica Capshaw), Meredith (Ellen Pompeo) and Cristina (Sandra Oh), who certainly didn't expect to have to answer to anyone once they took over the hospital. "They question his ability to manage the situation because of his lack of maturity and the position he is in because of his mother," Dempsey says. "There's a lot of resentment towards him in that position because of it."

"Jackson's anticipating a little bit of resentment and awkwardness," Williams adds. Jackson's relationships with Alex (Justin Chambers), April (Sarah Drew), Stephanie (Jerrika Hinton) and Webber (James Pickens Jr.) will be especially tested. "Not everyone is going to welcome that with applause. He's going to try to put his best foot forward and earn their respect, instead of feeling entitled to it. Over time, Jackson quickly feels like it's getting out from under him. It's too much and it's happening very fast. There's a lot more to lose than there is to gain."

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But Jackson won't be the only one feeling the backlash from his mother's decision. Surprisingly, the group will also feel the hate from the rest of the hospital considering it's technically their fault that Jackson is now in charge. "It's tricky because they were looking out for the hospital and the bigger picture," Ramirez says. "They had to make a really quick decision. Now Jackson has more say than [they do], and he can veto anything they say. You can sort of blame the group, but you can't at the same time."

Callie, in particular, will be wary of Jackson's position since one of Jackson's first acts as the head of the board is to keep the ER closed. "Callie is really skeptical about the whole thing," Ramirez says. "She doesn't really take him seriously and thinks his mother is behind the whole thing. He's basically a mouthpiece for his mother. It takes her a while to see past all of the initial frustration and distrust to actually see that something good might actually come out of him being a leader."

But keeping the ER closed is the least of the group's worries.  TVGuide.com was on set for their first board meeting in which — spoiler alert! — the Harper Avery Foundation enlists Jackson to oust Owen (Kevin McKidd) from the hospital. "Jackson will be really conflicted," Williams says. "Jackson definitely has loyalty to Owen. Owen's always been great to him and has always treated him with respect and high hopes, so that's something where it wakes Jackson up."

"Owen has really risen to the challenge of being the Chief. He's done a great job, so they'll go to bat for him," Capshaw says, stressing that Owen protected the group during the sale and they'll do their best to pay in kind.

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Going up against the group — and really, the whole hospital — when it comes to these two decisions may help Jackson to realize the opportunity he now has at the hospital. "For the moment, he's just trying to stay above water, so he toes the party line, but then he realizes he needs to draw a line and stand for something and get Owen back," Williams says. "That's the first marker of Jackson's leadership and loyalty and demonstrating that if you're going to captain the ship, you have to captain the whole ship."

How do you think Jackson will do being in charge? And do you think it'll last? Hit the comments!

Grey's Anatomy airs Thursdays at 9/8c on ABC.