This starts at the last episode right after OA was shot:

OA and Maggie were headed to the hospital to check out OA after he got shot in the vest. He should have known better than to jump in front of a kid with a gun. Others could have been hurt. She could have been hurt. Maggie knew that her feelings for OA were not exactly what they should be. She knew that she should only be concerned for him as a partner, not more. When OA fell to the ground, she knew her first task needed to be to secure the shooter, but she wanted to run to OA first. She wanted to know that he was ok. The seconds seemed long until someone came to help with the shooter.

OA- I knew better than to charge at that kid, but the way he was acting was making me worry for Maggie...not just for Maggie for everyone. She was all that I cared about and it was beginning to cloud my judgment. I knew she was freaked out when she ran over and ripped off my vest. I could see it in her eyes there was something more than just concern for your partner, but I wasn't ready to bring it up to her yet. I didn't know how she would handle the emotions that I felt for her. Would it ruin our partnership if I say anything?

Maggie- The doctors said he was fine and the ribs would just be bruised for a couple of days. It could have been worse had the gun been any bigger or the ammo and stronger. He didn't know how close he came. We started to walk down the hospital corridor when the shooter's Dad appeared. OA told him that his son was in the psych ward and that he should be up there. What I wasn't prepared for was the gun. I didn't realize that the son had been playing off his dad's beliefs. His dad played such a sorrowful role that it didn't seem that he had directed his son to do the shooting. In the time it took all of this to run through my head, the gun was pointed at OA and the trigger was slowly being pulled. The instinct took over to protect the wounded and I jumped in front of OA as the gun went off. I felt the searing cold first and then it just stung like hell. I could see OA grab my gun and shoot the father in the head, that was the end of that guy. OA was screaming for help and I could feel one of his hands on the new wound that was in my abdomen and the other holding my head. I could see the same concern that I had for him earlier in his eyes. I didn't know if it was something more or not but now didn't seem like the time to talk out our feelings. I knew there was a lot of blood by the wet feeling on my arm, but that meant that the bullet exited me. Did it go into OA? Was he hurt? I couldn't tell if the blood that was now spreading all over him was just mine or his? I tried to ask him, but it felt like my voice was totally gone. Words were getting caught in my throat with something else and confusion was sinking in. I tried to tell OA that I was struggling to breathe, but he seemed to already know this. There was suddenly a flood of people around me in white and blue and things were starting to get slightly hazy. I knew that I should just relax and let the doctors do their work, but that wasn't me. I was fighting the feeling of sleep and trying to fight, but OA kept telling me to relax and that everything would be ok. That the best place to be shot of course was a hospital and the best people were here to save me. I felt myself getting lifted onto a stretcher and then my hand felt cold suddenly. I realized that OA had been holding my hand and that the comfort that I felt was just whisked away. I wanted to go back. I wanted to be back near him and safe, but these people were taking me away. I didn't even feel the IV needle go in and the sedative drugs given. Who knows what happened next.

OA- I saw the gun being pointed at me and was shocked and confused. I wished I had gotten my gun back before they took me in for the examination, then I could protect myself. I felt suddenly vulnerable and knew that Maggie had hers. I didn't understand at first why the father of the kid I saved was pointing a gun at me and then I realized that the kid was following his dad. I braced myself for Maggie to pull out her weapon and start a standoff with this guy, but she didn't. When I didn't see her gun come out I braced myself for the new injury I was right about to gain. I saw him point the gun at me and pull the trigger. I heard the bang and saw the flash, but nothing came. I didn't feel any pain, where was the bullet. The milliseconds I had closed my eyes were the ones that Maggie used to jump in front of me. She used her own body to shield me. Why? She knew that I was "injured", but I could still protect myself. I dropped to the ground to grab Maggie's gun to end the guy before he could end me. The second he dropped and the gun skirted away from him, I took all my focus to Maggie. I could already see the blood pouring out of the bullet wound in her chest. I knew she was probably critically hit and that I needed medical help immediately. I called for help and doctors and made eye contact with a passing nurse who had heard the gunshots. I told her that the gunman was down and that I had an agent down that needed help immediately. She nodded and ran to get help. It was just me and Maggie for what felt like 10 minutes. I was talking to her telling her it was ok. That the best place to get shot would be a hospital. I saw a slight grin and then what looked like her trying to talk. All that came out though was blood. I knew at that moment that her lung had been hit and she was struggling to breathe. I screamed so loud for help I swear that the people outside the hospital had heard me. I didn't even see the doctors already running at us with what seemed an army behind them. The doctors pushed me back so that they could get in and see what was happening. They intubated her so quickly and had gauze on her wound and I felt helpless. I just held her hand telling her it was ok and that she was going to be fine. They whisked her away to surgery as fast as they could knowing that she was an FBI agent and the most important person at that moment.