Derek, in a voiceover, said life was full of choices and the last was whether to live or die. He struggled to breathe while Mr. Clark pointed the gun at Dr. Kepner, who rapidly threw out facts about her her life, her family, where she was from, and begged Mr. Clark not to kill her. He told her to run, so she did. Mr. Clark saw the SWAT team enter the hospital, so he turned and walked away, leaving Derek clinging to life.
Cristina tried to keep Meredith from going after Derek, and told her that if she wanted to leave she'd have to go through her. So Meredith grabbed Cristina and tossed her against a wall and ran to find Derek.
Meredith got to Derek and told him to stay alive. Cristina caught up to her and saw how much blood Derek had lost and knew they had to operate on him quickly. She went to get a wheelchair and found Kepner, who was still in shock.
Alex told Sloan to eat more bacon and have more sex because you never know when you're going to die. Lexie ran into Mr. Clark in the hallway and immediately recognized him. He told her he didn't mean to kill all those people. He only meant to kill Derek and Dr. Webber -- and Lexie. He said she was the one who unplugged his wife's respirator, that her hands killed his wife. He raised his gun and Lexie took a deep breath and closed her eyes. Then -- a gunshot. But we next saw Lexie hiding and Mr. Clark lying on the ground. A SWAT team member signaled to Lexie to move away, so she did.
Lexie went back into the room and told Alex to pull through. She said the whole thing was her fault because she pulled the plug on his wife. She told Alex she loved him and begged him not to die.
In peds, Callie and Arizona were treating their patient when Mr. Clark walked in. Arizona saw the gun and told him, "There are only children here." She then turned around and covered the litle girl with her body, repeating over and over "There are only children here". Callie carefully and quietly gave Mr. Clark bandages and told him to press them to the wound and go. He thanked her and left. Callie went back to calm the little girl and Arizona, by talking about how great of a doctor she is and talked about her magical smile.
Cristina made the plan to find Teddy and operate on Derek. He was holding on, laying on the surgical table, and asked Meredith to kiss him. Cristina and Kepner found Avery, who told them there was no attending surgeon on the floor. They decided Cristina was going to operate on Derek.
Cristina braced herself for the surgery and told Meredith she couldn't be in the room. She gave Kepner orders to keep Meredith out of the room.
Alex was in shock and looked up to see Lexie, but was saying, "Izzie, I'm sorry." He asked her not to leave him again. Lexie cried as she played along. A SWAT team member came into the room and told Lexie and Sloan their floor was clear and they were being evacuated.
Dr. Webber was outside talking to the cops, but when the commanding officer turned to find him again, he was gone. Hunt and Teddy made it out of the hospital but Hunt wanted to go back in for Cristina. Teddy told him he should, so he did.
Webber was inside the hospital too. Meredith told Kepner to stop crying, that Derek was Meredith's husband, and that Kepner didn't get to cry over him. Kepner told Meredith that Reed was her "best friend and she died today." Meredith held her hand.
Sloan and Lexie brought Alex outside and Alex was taken to another hospital. In surgery, Cristina found the bullet right next to the aorta and she didn't know what to do but she made a plan.
Bailey and Mary, meanwhile, were dragging Charles through the hallway but when they got to the elevators, they were off. Bailey freaked out for a moment, then gathered herself and went to sit with Charles. When he asked if he was dying, she said yes. She told him she and Mary were going to stay with him.
Hunt showed up and Meredith told him what was going on. He looked through the window and said she appeared to be doing fine but he'd go in to see what he could do to help. When Hunt went inside, we saw that Mr. Clark was in the room with a gun to Cristina's head, shouting at her to stop fixing Derek and to let him die. Cristina and Avery refused to stop working. Hunt told Mr Clark that if he shot Christina, that he would kill him.
Mr. Clark told Hunt that he'd shoot him first and then Cristina but he really only wanted to kill Derek. "An eye for an eye," he said. Meredith then came into the room and told Mr. Clark to shoot her. She explained that she's Lexie's sister, she's the closest thing Webber has to a daughter, and she's Derek's wife.
"If you want them to hurt the way you hurt, shoot me," she told him. "I'm your eye for an eye."
He turned the gun toward Meredith, but Cristina said Meredith was pregnant. Hunt made a move toward Mr. Clark and was shot. Cristina and Avery then raised their hands and Avery told Mr. Clark that Derek would die and he could watch it happen on the monitor. Derek flat-lined and Meredith cried almost hysterically. Mr. Clark walked out.
When he was gone Avery reattached Derek's heart monitors and his pulse reappeared on the screen. Cristina went back to work and asked Meredith to check on Hunt and see if he was dead. Meredith said he was alive and Cristina asked her to take him to another O.R. and fix him. Cristina then asked Avery to remind her to thank him later.
Charles was still dying and told Bailey that he didn't hurt anymore, which he knew was a bad sign. He asked Bailey to find Reed afterward and let her know he always had a crush on her and he didn't think she knew. Mary said Reed knew because girls always know. Charles died.
Meredith was trying to treat Hunt's gunshot when she felt a strong pain. Kepner was worried Meredith had been shot, then discovered blood spreading down Meredith's thighs. Meredith knew she was having a miscarriage but still proceeded to work on Hunt.
Webber walked through the halls of the hospital and found some bodies. He found Mr. Clark, who told him he'd bought the gun at a superstore and bought extra ammo because it was on sale. He said he couldn't bring it all in his pockets because he wanted to bring his flask. He asked Webber to open it for him and Webber did. Mr. Clark took a swig and said he wasn't much of a drinker, but figured he'd need some "liquid courage." He offered Webber a drink and he declined.
Mr. Clark told Webber he only had one bullet left. He said he planned on shooting Webber, then himself.
"Then it seems you have a bit of a problem," Webber said.
Mr. Clark offered Webber a drink again. He took the flask, smelled the vodka and spilled it out. Webber told Mr. Clark his choice was really between a life in prison or a possible afterlife with his wife. The SWAT team walked in and we heard a gunshot, but didn't see what happened.
Derek went into shock and needed to be defibrillated.
Meanwhile, Mary reunited with her husband outside the hospital, Bailey searched for Reed, Callie and Arizona had a moment and talked about having "all kinds of kids."
Derek's heartbeat returned to normal. Everyone sighed, including Hunt and Meredith, who were now in the room.
We see the bridge cordoned off with yellow crime scene tape. Webber walked and saw Derek's blood stain as police took pictures. I guess we know what choice Mr Clark made. The commanding officer found him and shook his hand.
Mark and Lexie showed up at the other hospital. Alex was out of surgery. Lexie went to Alex. Mark watched Lexie take Alex's hand.
Meredith took another look at her positive pregnancy test as Derek's voiceover repeated, "Human life is made up of choices: Live or die, that's the important choice."
As Meredith tossed the pregnancy stick in the trash, Derek's voiceover said, "...and it's not always in our hands."