This one is from season 7's "A Thin Line" episode.

"The human capacity for guilt is such that people can always find ways to blame themselves." – Stephen Hawking

I watch as he falls to the ground and his gun drops from his hand. A moment later, I've kicked his gun out of reach and am feeling for a pulse on his neck. There's one there, but it's very faint. I glance to the side and find JJ helping up Ms. Ross – who is shaking quite badly – from the ground where Mills had shoved her.

"Ma'am, are you okay?"

She nods shakily in reply, and I find JJ's eyes instantly. "Watch him. He's not gone yet," I order, getting to my feet quickly. As I rise, I stow my weapon back into its holster and head immediately for the stairs, taking them two at a time as I head back down to the main floor.

I'm so intent on making it down the stairs as quickly as possible that I almost don't notice Prentiss at the bottom of the staircase, leaning on the wall, her gun still drawn. I don't miss, however, the pained expression on her face.

"Prentiss," I say in surprise as I manage to avoid running right into her. "What the hell are you doing?"

"Backing up my partner. What does it look like I'm doing?" she says with a tired grin as she begins to holster her gun.

"Are you okay?" I say in concern, my brows knitting into a frown as I recall how I spied her on the ground when I came into the house.

"I'm fine," she says, waving off my concern after holstering her weapon.

"She got hit," JJ calls from upstairs, and Prentiss looks up toward the second floor with an annoyed expression.

"I'm fine," she huffs, holding out a hand and cutting me off before I can even begin to speak.

"The paramedics will be the judge of that," I say firmly. "Where were you hit?"

"It just grazed my arm," she says. "Mills?"

"Not a threat anymore," I answer quickly. "Now let's head out front to catch the medics," I finish, stepping toward her and putting my hand on her lower back to guide her toward the front door.

"Honestly, Morgan, I'm fine."

"Let me see then," I say in frustration when she steps away from me.

"Look," she says, gesturing to her arm that's still covered by her shirt, "no blood, and no gaping wound. I'm fine."

"You're going to the hospital," I say firmly, leaving no room for argument. But as usual she still manages to somehow find room.

"No I'm not," she replies defiantly. "I'm fine."

"Emily," I reply with a glare, "either you get in an ambulance yourself and let the paramedics check you out, or I carry you over there myself. Either way, you're going to get checked out."

"I'd like to see you try," she says, fire dancing her eyes. I suppress a groan of frustration – this woman was downright infuriating at times. I wish she could understand the way my heart dropped when I saw her on the ground. I wish she could understand that I need to know she's okay.

"Don't think I won't do it, Prentiss. Because I will."

Her eyes narrow as she holds my gaze. Neither of us is budging, and I don't foresee either of us giving in any time soon. Maybe JJ was right – we're far too similar for our own good.

"I don't need to go, Morgan. Honestly, I've had worse injuries from moving furniture."

"You got shot."

"It was a graze," she corrects, shooting me an angry expression.

"Graze, my ass," I say as my eyes hone in on the entry point of the bullet in her arm now that her shirt has shifted slightly. From what I can see, it's a lot more serious than a graze. "The bullet went through your arm. Let's go."

"I can wait. Let's get everything settled here first."

"Emily," I grind out as I clench my teeth in frustration. I close my eyes for a moment and let out a heavy sigh. "Please," I finish, unable to keep my tone from starting to sound just a touch desperate. Visions of her lying on a warehouse floor, no matter how different and distinct from the current situation, dance in my head.

Her eyes widen fractionally as she no doubt detects that shift in my tone. "Okay," she agrees quietly. "I'll go get checked out. You go help JJ."

I blink in surprise. I hadn't expected her to give in to my request so easily. "JJ's fine, I'll come with you."

"Derek," she says gently, "go help JJ. I'll be okay. I'll go see the medics and get them to look at it."

"Em, just..." I trail off, trying to find a way to explain that I need to make sure she's okay. After seeing her in that warehouse and subsequently watching her code in the ambulance, I need some peace of mind that this tiny little bullet isn't going to undo the fact that we just got her back. "Humour me, please."

She lets out a light huff of frustration and I swear I see her roll her eyes. It's oddly comforting to see her seemingly blasé response to her injury. It reassures me that little bit that it's not life threatening. She's not telling me to let her go, and accepting her fate to die at the hands of a terrible man. "Okay. Let's get this over with."

The two of us make our way out front and find the paramedics just arriving. I flag them down, and a guy that looks entirely too young to be qualified as a paramedic hops out of the ambulance.

"Agent," he greets me with a nod. "What's the situation?"

"She needs to get her arm checked out," I say firmly. "No disrespect, but you look a little young…how old are you exactly?"

"What kind of wound are we looking at here?" he asks, ignoring my question, much to my chagrin.

"It's just a graze," Emily answers quickly.

"Don't listen to her. She's in denial. It's more than a graze," I say sternly, shooting her an unimpressed look. "I'm pretty sure it went right through the arm."

"She is right here, and can answer the man's questions for herself, thank you."

"Then don't lie to him, Emily."

"Morgan!" she says loudly, her frustration with my overprotectiveness finally bubbling over.

"Uh, I honestly don't care if you guys keep arguing, but I do need to check out your arm, so can you take a seat here, please?" the paramedic interrupts.

"Sorry, he was just leaving," Emily says, shooting me a look daring me to disagree. Unfortunately for her, my stubborn streak is exceptionally strong tonight. It always is where Emily Prentiss is concerned.

"Nah, I'm good. Exactly how long have you been a paramedic?"

"Long enough to know what I'm doing, if that's what you're asking. Okay if I cut off your sleeve? It'll be easier than you trying to get the arm out of it, I think."

"Morgan, leave him alone. I'm sure he's more than capable," she says, shooting me an irritated look. "Go ahead," she says, turning her gaze to the paramedic.

"What? I'm just making sure he's not going to make you lose your arm or something."

She rolls her eyes and lets out an exhale as her eyes swing back to me. "You're ridiculous sometimes, you know that?"

"No more ridiculous than you, crazy lady."

"Feel free to kick him out at any time," Emily says, catching the paramedic's eyes.

"Kick me out? Kick me outta what? We're outside."

"The area?" she suggests cheekily. "Ow," she exclaims as the paramedic gently prods around the wound.

"Careful, man," I chastise.

"Morgan," she says with a glare. "Let him do his job."

"Sorry," the paramedic apologizes. "We're going to have to get you to the hospital to get it stitched up. It's a little more than we're prepped for here. I can take you since we've got a second rig on its way here."

"Don't even think about it," Emily warns me as she gets situated in the back of the ambulance. "I don't need an escort. I'll call Rossi to pick me up once I'm cleared."

"Don't-" I start, but am interrupted immediately.

"Morgan, so help me, I'm going to smack you if you get in this ambulance."

I hold my hands up in surrender and let out a breath. "All right, all right."

"Derek?" she says after a moment. Her tone isn't the frustrated and annoyed one she just used. It's softer, and almost unsure sounding.

"Yeah?"

"Thank you."

"For what?"

"For caring enough to be a pain in my ass," she answers with a smile.

"Always," I answer immediately, mirroring her smile.

I watch as the ambulance drives away and am immediately hit with waves of guilt. I'd made the call to split us up. I'd made the decision that led to her getting shot. To her getting hurt. Again. I rub my eyes as the weight of that settles on my shoulders. I'd failed her once when I let Doyle nearly kill her and let him escape, and I'd failed her again today.

I vow to never let her be put into a situation like that again where she could be hurt. And I promise myself that I'll apologize when I see her. It's the least I owe her after what my decisions had led to. I only hope she can forgive me.

So...what did you think? I never bought that Prentiss just sat around and waited until Morgan and JJ handled things. I always figured she'd at least try to get up and provide backup. This conversation is the result of my wondering how that scene might've gone if they'd shown that little bit extra of Prentiss helping out.