A/N: Some Destiel overtones here, so you can choose to accept this as a 'canon' part of the series or not, but it bridges the gap a little between The Physician and The Surgeon.

The bunker's empty when Dean gets back. He's half disappointed and half relieved that Sam isn't there to greet him, but it at least spares him having to craft some lie about how the fictional hunt went or how Rudy was or whatever. It doesn't take him long to dump his stuff and head to the kitchen in search of a bottle of cheap whisky, and he gets as far as taking out a tumbler and opening the liquor cabinet when he realises the bunker isn't as empty as he thought.

"Hello, Dean."

The voice comes from behind him. Dean isn't startled, but turns slowly, an eyebrow raised as his gaze comes to rest on the angel standing there. "Cas. Didn't expect to find you here." Given that, you know, you're never around anymore.

Cas' expression is impassive, and Dean doubts it would be any different even if he had said that last part out loud. "There are some rogue angels in Missouri that need bringing back to Heaven. It was en route. I thought I'd call to check in, but Sam said you weren't around so I decided to stay and wait. Hannah is seeing to business."

Hannah, huh? Dean would ask, but finds he doesn't really care. "Where is Sam, anyway?"

"At a bar, I believe. He seemed…put out, that you went on a hunt without him."

That's the part that makes Dean shift uncomfortably. Looks like he will have to lie, after all. "Yeah, well, Rudy called and it wasn't really a case that needed three hunters. No point dragging Sam all the way up to Chicago just for that." Cas cocks an eyebrow, and Dean finds he doesn't like the way he's being scrutinised. He's had enough people give him that look today.

"I think it bothers him because last time you went off without him, it was with Crowley."

Dean scowls. "Thanks for the reminder, Cas. If Sam didn't like it, he can deal. It was just a hunt."

"Was it?" Dean's heart skips at the sudden suspicion in Cas' voice. "Because I know you weren't with Rudy."

Dean's mouth has gone dry. He turns back to trying to pour himself a drink. "That's bullshit, Cas."

"You can lie to your brother, Dean, but not to me."

There's a pause as Dean finishes pouring his glass of whisky and then takes a draught of it. He's busted, and he knows it, even if he doesn't know how. "You know, for a guy who's so bad at lying, you sure are good at spotting it."

A disconcerting crease forms between Cas' eyebrows. "So where were you?"

Dean sighs and takes another gulp of his drink. What even was the point in lying, at this point? "I went to see a doctor."

Cas' look of suspicion suddenly softens, quickly replaced by concern, and Dean thinks that might even be worse. "A doctor? Why?"

"Doesn't matter. I'm fine."

"Dean…" Cas lets out a heavy sigh. "Just a few weeks ago, you were a demon, and I know the process of fixing that wasn't easy on you. If you're having health concerns, you should tell me. I can help."

Dean almost wishes that he could. He wishes that he'd just gone to Cas in the first place and they'd been able to fix this whole thing, but he knows life is never that easy. He gulps down the rest of the liquor and sets down the glass as he decides to just come clean. "Alright. I had my heart checked. I've been getting palpitations, sometimes on hunts, sometimes just for no apparent reason, so I wanted to check there was nothing weird going on."

Now Dean can only describe Cas expression' as pure exasperation. "And is there?"

"No. I don't know. She's given me some pills. I'll be fine."

Unconvinced, Cas steps closer, a hand flying up to touch Dean's throat. "How can you be sure?" the angel growls, and Dean realises Cas is taking his pulse.

Annoyed, Dean swats his hand away. "I'm sure. Leave it, Cas."

"And this 'doctor', was she a hunter? Did she know about the life and what you do? About your history?"

"Not exactly…"

Cas' eyes narrow. "What does that mean, Dean?"

Dean braces himself, knowing this is the part that's really going to set Cas off. "She's a demon doctor. Someone Crowley mentioned a while back."

Predictably, Cas' jaw clenches and his eyes narrow further. "You went to see a demon?!"

"No! She's not a demon, she just treats them. Besides, it doesn't matter." He's trying to brush this off, but his nonchalance seems too forced to work. "It's done now, and she helped me, so can we please just drop this?" He moves as if to push past Cas, ready for this conversation to end, but the angel moves to stop him. Cas' hand comes to grip tightly on Dean's left arm as he forces Dean to meet his gaze.

"And you didn't think to come to me? Or Sam? You'd sooner trust a stranger who helps demons than the people who care about you?"

Guiltily, Dean's eyes flicker downwards. "This isn't something I want to trouble Sam with. And you…you have your grace to be worrying about, Cas. I can't ask you to heal me."

"But you could have least asked me to check on you," Cas says, eyes boring into Dean's with an anger and intensity that would make Dean wither, if only because he knows what it really means. How much Cas cares.

"Well, it's too late now," Dean says, gritting his teeth as he realises how much he truly does feel like crap now. "I had her check on me, and she didn't try to pull one over on me or stab me or anything," – at least not without me trying to stab her first – "So I've got my medication, and now if it's alright with you, I'm going to bed." He pushes past Cas with a huff, not looking back as he tries to stave off the guilty pit that's opened up in his stomach and wants to swallow him whole. He feels awful about the whole thing, and he's wondering if he really did make the right choice to go to Carter instead of going to Sam or Cas, but it's not like there's any way to take it back.

Cas lets him go, but for the second time that day, it seems to Dean that he can feel eyes lingering on him long after he's left the room.

Dean gets as far as his bedroom and stripping down to his t-shirt and boxers to climb into bed when Cas disturbs him again. It comes as a soft knock on the door, not waiting for an answer before it cracks open and Dean sees those bright blue eyes gazing softly at him. The anger seems to have gone. Now it's just all worry.

Dropping his gaze lower, Dean's eyes are drawn to Cas' hand, clutching a plain black stethoscope that he no doubt got from the infirmary, and Dean knows where this is going. He sighs again. "Well, hey there, Dr Sexy."

Cas quirks a confused eyebrow. "You think I'm sexy?"

"What? No. It's a TV show, man. I'm making a joke. Just…" He lets out a breath as he eyes the stethoscope warily. "I'm getting sick of the sight of those things."

The angel takes that as permission to enter, crossing to the bed and sitting down comfortably close to where Dean's just begun to climb in. "I know you'll insist you're fine, Dean, but please, if you've felt the need to see a doctor, let me examine you. As your friend, it's the least I could do."

Dean feels the guilt monster begin to gnaw at his insides again. If he lets Cas do this, then the angel's gonna see just how much he really was lying about everything being fine, but he still doesn't want to burden Cas with the truth. "Cas, man, look. I'm okay. Really, you don't have to…"

"Dean." Cas cuts him off firmly. "The more you say you're okay, the more I don't believe you. I'm not asking you to let me heal you, if there's really nothing to heal."

Cas' eyes are soft, imploring, and Dean knows there's no way he can keep this stubbornness up. In a way, it almost feels as if a weight has been lifted from his shoulders as he nods his permission and gestures for Cas to go ahead.

It isn't awkward as Cas puts on the stethoscope and moves to lift up Dean's shirt, the chestpiece feeling warm where it hits his skin in contrast to the coldness of earlier. He listens in silence for a few moments, eyes cast downwards as Dean draws steady breaths, before moving the diaphragm to a new spot on Dean's chest. "So, this doctor," Cas begins to say, eyes flickering up to meet Dean's again. "Was she 'sexy'?"

There's a beat, Dean unsure how to take that before his lips pull upwards into a smile. "Um…I guess. If you're into the whole 'creepy, slightly unhinged junkie' vibe, sure. Why not?"

Cas smiles back, chuckling as Dean at last seems to relax. "It's a TV show. I'm making a joke."

"I got that." Dean's grateful for the attempt to put him at ease as the stethoscope moves lower on his chest again. "How's it sounding?"

"Steady," Cas replies calmly. "There's a slight murmur in your triscuspid valve, but it seems benign. The rate and rhythm are good."

"Oh?" Dean barely manages to mask the surprise in his voice. He supposes the pills must be working, then. "So, can you put your mind at rest now?"

"I would hope so." Cas sighs as he pulls off the stethoscope and meets Dean's eyes, expression still full of concern. "You seem to be alright, but if you have any more concerns, Dean, any at all, you can come to me."

"Thanks, Cas." Dean means it, giving the angel a small but genuine smile. "Can I get some sleep now then? I had a long drive back."

"Of course." Cas returns the smile as he gets up to leave, but then Dean remembers something else.

"Oh, and Cas?"

The angel pauses, waiting.

"Can we not tell Sam? I will, just…not yet. When I'm ready."

Cas nods his understanding. "Not a word," he promises. "Sleep well, Dean."

Dean's already turned out the lamp on the nightstand by the time the door closes behind him. The darkness feels almost comforting as it creeps over him, leaving him with the sound of his heartbeat steady in his ears and the pit in his stomach seems a little more filled than before.

It's almost enough that he doesn't notice the flutter his heart gives just before the darkness sinks deeper into his consciousness and he's taken by sleep.