'Grey's Anatomy' : Kate Walsh's Addison Montgomery Returns as Tragedy Strikes Grey Sloan

The issue of abortion care was once again front and center on Thursday's Grey's Anatomy.

Dr. Addison Montgomery (Kate Walsh) returned to the hospital — but it wasn't all reunions and red hair. And frighteningly, multiple lives now hang in the balance.

Addison was visiting Grey Sloan Memorial Hospital to help teach a new group of trainees visiting from states where abortions were outlawed after Roe v. Wade was overturned. She and the rest of the doctors, including Miranda Bailey (Chandra Wilson), discovered a bunch of people outside the hospital protesting abortion rights.

When the hospital's security wanted her to shut down the clinic, Miranda called the new chief, Teddy Altman (Kim Raver), who instead requested that security call for backup and continue to try to keep the protestors at bay.

But their numbers continued to increase, and, eventually, their actions took a violent turn. Benson "Blue" Kwan (Harry Shum Jr.) was hit in the head with a brick that was thrown through a window of the clinic.

One trainee felt responsible for the protestors because she revealed Addison's location. (The former Private Practice doc had become somewhat famous for traveling in a mobile clinic and helping in states where abortions were illegal.) "I'm so, so sorry," the trainee told Blue. He replied, "I'm pretty sure you didn't throw it."

However, when she showed him her social media post about working with Addison, he told her that she gave protestors "a roadmap" to the hospital. With a guilty conscience, the trainee admitted she was considering quitting but Dr. Mika Yasuda (Midori Francis) told her to push forward because there will be fewer doctors to help without her.

Miranda also encouraged the trainees to stay strong, saying, "We are struggling as doctors, advocates for women and reproductive freedom… We need to lift each other up."

Addison was still struggling with the backlash to her medical care and admitted she now has a bulletproof vest after being attacked. She told Bailey, "I'm not gonna quit…patients need this care."

Mika and Dr. Jules Millin (Adelaide Kane) met with a pregnant woman who wanted an abortion at six weeks. However, she was bothered by the protestors and asked, "Is that going to go all day?"

As the patient prepared to take a pill for the abortion, she explained why she wasn't ready to be a mom and admitted she is working "through the lasting damage" from her relationship with her own mother.

The patient's friend Andrea — who was at the hospital to support her — went into labor but didn't want to give birth under these circumstances. She begged, "Please do not make me push." Miranda stepped in to comfort Andrea by singing, "The Lion Sleeps Tonight" which relaxed the patient enough to finally push.

When Addison found out Andrea was having a baby girl, she told her, "She is about to be welcomed by about 100 women and you" as she looked at Blue.

As the protestors began to clear out from in front of the hospital, Richard Webber (James Pickens Jr.) congratulated Chief Teddy Altman on "keeping everyone safe."

However, tragedy struck when the group exited the clinic. Addison stopped in the middle of the street to help one of the trainees pick up some dropped papers when a car ran them over, leaving the other doctors shell-shocked.

Whether or not Addison or the trainee will survive remains unknown.

Elsewhere, Nick Marsh (Scott Speedman) and Maggie Pierce (Kelly McCreary) treated a patient named Jessica who needed a lung transplant due to having pulmonary fibrosis. Her boyfriend offered to donate his lung but he was late for the surgery.

As they prepared for the transplant, Nick also confided in Maggie that he is worried about his future with Meredith Grey (Ellen Pompeo). However, she advised him to not lose hope, saying, "You love her. Don't give up."

Owen Hunt (Kevin McKidd) jumped into his role as Chief of Trauma and treated Ryan Jenkins — nicknamed R.J. — who had blunt force trauma to the chest from a car accident. He quickly realized that R.J. was in fact Jessica's boyfriend.

The accident made him no longer a candidate to donate his lung that day but Jessica was only concerned about his life. She pleaded to the doctors, "Please save him, do whatever it takes."

After insisting that he "just needs to be ok," she recalled their first kiss with Lucas Adams (Niko Terho) and Simone Griffin (Alexis Floyd) in the room.

"No one had ever kissed me like that. It changed my life in an instant," she shared as Simone raced out of the room seemingly overcome with recollections of the kisses she shared with Lucas.

She then decided that it was time to push her wedding date up, telling her fiancé Trey (Will Martinez) that they should get married next month.

He agreed, saying, "I will get to be your husband that much sooner."

Grey's Anatomy airs Thursdays at 9 p.m. ET on ABC.