Joe finds him sat outside on a low wall, the sun just setting over the horizon and casting long red ripples over the waves. There's a few people out in the sea, cutting dark shapes out in the water, and there's a warm breeze blowing in from the surf. It's a completely different atmosphere to the one in the darkened room with its screens and stern faces that he's just left, and the contrast is jarring.

"That's the first time you've seen SEALs in action, isn't it?" Joe says after a while, his voice gentle and knowing, and Danny opens his mouth but nothing comes out. He just nods and looks down at his hands, and swallows around the lump in his throat.

Because that's the thing. He's known Steve for over a year now, and he's seen the way that he goes about things in his own gung-ho way, ignoring procedure and doing things that he'd never be allowed to if they hadn't initially been granted full immunity – and he's always just chalked it up to Steve's SEAL training. He's always said to himself that this is how SEALs operate, Steve can't function in normal society because he's spent too long underwater, and it's a good job that Danny's around to keep him in check or there'd be utter carnage on the island.

But that's not true, and Danny can see now that he's never seen a SEAL in action, not really – he's seen Steve, but it's just Steve, and not Steve-the-SEAL. The distinction has never been so obvious before.

"I thought that," he starts, and has to pause to clear his throat. His voice sounds dry and cracked and pained. "I always thought that Steve was crazy and dysfunctional because of his training. But it's not, is it? That's just him."

"Not quite," Joe says, and his smile is indulgently fond. "He was socially inept before Hell Week started, which is in part due to do with his father sending him away, and his natural bull-headed nature. But he's a trained soldier, Detective – you send him out on an op with his teammates and you give him his orders, and he will kill people without blinking as readily as any of those men that you just watched on screen."

"I know that," he says and his tone comes out as somewhat defensive. "I know that SEALs are super-tough and everything and I know the vague stuff that they're sent to do, and I know that Steve was in Team Six and I've heard about the sorts of things that they do, not to mention he's implied that he was in Special Activities at one point, but he's not... he's not like those soldiers back there."

"He is exactly like them," Joe barks suddenly, and his face has grown hard and unrelenting. "He was trained to be like that and he will always have the same instincts; it's drilled into him in ways that you can't imagine. Some SEALs, when they return to civilian life, just can't cope. They can't readjust to normal life and everything breaks down around them – you're lucky that Steve knows the difference, that he can rein it all in and act relatively normal. You told me that Clay Garcia's wife couldn't cope with how often he was away? She's in the minority. Most can't cope once their husbands come back."

"So what, first he's socially inept, and now we're lucky that he's so good with people? We must be talking about different people because the man keeps grenades in my car!" Danny snaps, and Joe gives him a side-eye.

"I'm saying that Steve adapts easily; better than most in his situation. But that doesn't mean that you should ever underestimate him. You've only seen a fraction of what that man is capable of, and you have no idea about the things that he's done in the past."

"Which is exactly why I asked him about it, because you're right, I have absolutely no idea and as a rule I like to know things about my partner, I like to know about their past and the sorts of things that they've got up to, and I think it's a fairly human reaction to wonder what the hell Strawberry Fields was."

"But he wouldn't tell you," Joe points out, and Danny takes a moment to stop prodding at the dusty floor with his toe to glare at him for rubbing salt in the wound. He continues blithely. "Even if his operations weren't classified, he'll likely never tell you about them. He's not a blood knight, Detective Williams – he may be extremely good at what he does, but that doesn't mean that he enjoys it. He's done some terrible things, and I'd wager that many of them he'd like to forget."

"He kills an average of one criminal every ten days, I'm not going to believe that this guy is going to start crying over the death of one terrorist."

Joe fixes him with a look, then – and Danny knows that he's being facetious and argumentative, but he's tired and he's stressed and too much is going wrong all in such a short space of time. He doesn't have the patience right now to be accommodating or understanding; he's just looking for an argument to fill the spaces.

"Imagine this," Joe says, his voice tight. "You're coming close to bringing down the head of a terrorist organisation. You're in position at the compound, you're ready to roll, everything's going fine. But it turns out their security is better than you thought, they've become aware of you, and someone shouts down to you that if you come any closer, they'll shoot a little girl. You can hear her screaming; you're in a position where you can see her crying, can see the gun pointed to her head. You don't doubt that he's bluffing, and you only have two choices – back off, or move forward. If you move back then the little girl might live but if you move forward, she will die. As a police officer and a father, what would you do?"

"I'd want to save the little girl, if I could."

"And what do you think a SEAL would do?"

"You're saying that Steve would allow the girl to be killed?"

"I'm not saying that he'd do anything. I'm not even saying that he's ever been in that situation before. But have you stopped to consider that perhaps he's ashamed of some of the things that he's done? Or that maybe you won't like what you hear?"

And Danny hasn't got a clue how to respond to that because no. He hadn't. He feels a sudden and vicious wave of anger at himself and his own wilful ignorance. There are things that they sometimes encounter in their day-to-day life that he wouldn't want people to know about, and they're just a taskforce – Steve was involved in black operations for several years of his life. He's probably seen the very worst of humanity, from his own side and the other and possibly even in himself, and that's a sobering and unexpected thought.

"I don't know what reason you've concocted in your head for why he's shut himself off and locked down since you found his file, but it'll be wrong," Joe continues, and his voice has returned to its original, reassuring tone. "You might think that he's not telling you about Strawberry Fields just to be an asshole, but you'll be wrong. So do yourself a favour, and don't ask him to tell you about his operations again. It's not fair on either of you."

Danny finally lifts his head to glance at Joe, but the man is looking in the complete opposite direction – he's looking at the main door a few yards away, where Steve has just exited with a few other soldiers, deep in conversation. Danny pushes himself to his feet as Steve approaches, brushes the dust off his trousers and tries not to look awkward.

Steve says something to the others as he noticed Danny wandering across and they leave without a word, peeling off and heading in different directions. His expression hasn't changed since they left El Camaleon's hideout, still locked down and utterly unreadable, and it makes Danny's stomach do an uncomfortable little flip.

"Chin and Lori?" Steve asks abruptly, and Danny rubs at the back of his head.

"Left a good half hour ago," he says, and Steve grunts in response. "So I was thinking, it's been a long day and I'm sure you're tired from jumping out of helicopters to catch guys falling from the sky, so how does beer and this morning's game sound to you? Like a good plan?"

Steve just stares at him, with his face still closed and stern and his whole body tensed and ready to fight, and for a moment Danny thinks that this is really the wrong call to make. But then Steve blinks and the tension flows from his bones in one rippling movement, and his face breaks out into a smile that eases the tight band around Danny's chest.

"Sounds like your only good one this week," Steve says, and everything about him seems to relax at once, and it's almost like today hasn't happened. Steve holds his hand out, and Danny throws his keys across to him without even thinking about it.

"Having suggested it, do we even have any beers in, or do we need to swing by and grabs some?"

"I restocked the other day when I went for Gracie-safe food. We're still picking her up tomorrow, right?"

"Uh, yeah. Yeah, we are," Danny says, and looks out of the window as they pull away from the base as he realises that he doesn't care what Steve would do in that imaginary situation with the little girl. Because he knows exactly what Steve would do for his little girl, and for him, and for his team, and that's enough for him.

Strawberry Fields aren't important.