Harry Shum Jr. is officially scrubbing in!
In this week's issue of PEOPLE, the Glee alum, 40, opens up about starring in the upcoming 19th season of Grey's Anatomy as surgical intern Benson "Blue" Kwan, what fans can expect this time around, and the sweet welcome he received from star Ellen Pompeo.
"For a show that's been on for this long, you would think, 'Okay, everyone is just doing the same thing.' But coming on to set, it was a completely different energy that I was expecting," says Shum. "Even the actors that have been there since the beginning were not just welcoming, but also invigorated."
"The writers are really crafting some really interesting and fresh takes, while also infusing in the storylines that I think people have grown to love or find some comfort in as well," he adds.
In July, ABC announced that Shum would be joining the Grey's cast as Benson "Blue" Kwan, beside fellow additions Adelaide Kane, Alexis Floyd, Niko Terho and Midori Francis — all of whom will play first-year surgical residents at Grey Sloan Memorial.
A news release at the time described Shum's character as a "sharp-witted, impatient, and brilliant first-year surgical resident at Grey Sloan." It continued: "He's generous by nature but competitive to a fault, naturally gifted, and used to winning at everything. A family crisis interfered with his career plans and now he's got a lot to prove."
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Speaking to PEOPLE about taking on the role of Blue, Shum says, "He's used to winning blue ribbons, and medals, and being number one until his mother died, and tragically. It just destroyed him and he hit a wall."
"And so he's a little later as an intern and coming into this, and has a hopeful life," he continues. "All the interns have a hopeful life that they've crafted that we're going to explore. I'm really excited to dive deeper into it because it just gives so much wealth to figure out who these people are and why they even decide to become doctors."
Shum says he started watching Grey's during the first season "when it was magic," but his awe hasn't faded in the seasons since.
"There's a level of current events, the things that they keep talking about, and it's a testament to the writer's room," he shares. "I think the people involved in telling these stories, and also contributing in ways that go beyond just writing them out ... everyone is fully invested."
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Among those invested are Grey's veterans Pompeo, Chandra Wilson and James Pickens Jr.
"The first day we got to meet Chandra and James and it was iconic," says Shum. "It was an iconic moment. Chandra, she just gave us this beautiful, just very, almost life advice of just be yourself on set, on the show, and try and contribute in so many ways that feel very true to yourself. I think that's why the show has gone on for so long. I think that advice has been given over time and has been utilized in so many beautiful ways."
Another memorable moment for Shum during his first day on set was meeting Pompeo, 52.
"The first day, she gave us a beautiful plant that all of the interns have, so we just try to make sure that it's healthy and staying alive throughout the whole season," Shum explains. "Her first day, she had this massive monologue, pages and pages, and she was just so gracious with her time, and giving us advice, and just welcoming us to the OR."
"I look at her as someone who's so iconic, who's been doing this for so many years, but still again, having such a fresh energy, which is really inspiring," he adds.
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During the season 18 finale in May, the Grey Sloan Memorial's residency program was shut down by the review board leaving quite a few residents orphaned, including Levi Schmitt (Jake Borelli), Taryn Helm (Jaicy Elliot) and Mabel Tsang (Sylvia Kwan).
The end of season 18 also saw Miranda Bailey (Wilson) quit as Chief of Surgery, leaving Meredith Grey (Pompeo) in charge.
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Earlier this month, ABC announced that Pompeo will have a scaled-back role in the forthcoming season and will appear in only eight episodes.
Season 19 of Grey's Anatomy premieres Oct. 6 at 9 p.m. ET on ABC.