"Kiss, Kiss, Bang, Bang" reestablishes the relationships between the Torchwood characters, while taking those relationships a step further. In the process it highlights some of the mirrors and parallels between the characters.
Jack/Owen
Jack and Owen were an obvious parallel in the first series. It was pretty clear to me that Owen was meant to be like Jack was before he met the Doctor, and that the reason Jack didn't punish him as many wanted was because he wasn't nearly as bad as Jack had been. The conversations between Jack and John show that Owen was indeed only a pale copy of the dark and dangerous man that Jack had been.
In KKBB this parallel is carried further. Owen announces that he's become aware of the diminishing returns associated with his former lifestyle and is looking to settle down with "a proper woman". (That he tells this to Toshiko, who has a crush on him, is significant. Settling down is a major theme of this episode.) Owen appears to be at a point similar to where Jack was at the start of The Empty Child -- aware that his lifestyle is getting him nowhere, aware that he needs to stop, but not sure how. This is consistant with the impression I got of Jack when he meets the Doctor -- not that Jack is a bad con man as many have speculated, but that he was too tired of the game to want to carry it on past that point. Jack was already looking for something different at that point, as Owen is at this point.
Jack/John/Jack's younger self
Jack and John are former lovers who must have parted on good terms, otherwise they would have killed each other. The interesting thing here is how Jack and John are never, ever alone, even when they appear to be. There is a never-named ghost whose presence hangs heavy in the room, and that is the man Jack used to be.
John is not aware of this presence until the autopsy room scene, thinking that the Jack in front of him is basically the Jack he knows. But Jack is always hyper aware that he is no longer the man John remembers. Jack now loathes the man he used to be, He may have made his peace with the Doctor, but he clearly hasn't made his peace with his former life. And with good reason as there are hints that Jack used to be worse than John was then. "He's a reminder of my past. I want him gone."
It seems to me that much of the time that Jack is talking to John, he is actually talking to his younger self. "These people, this planet, [snarl]all the beauty you could never see[/snarl]. That's what I come back for." Whose blindness is Jack angry with here? John to a certain extent, but it seems to me that most of his anger is directed at himself. John is only a convenient (and even better, deserving) substitute.
Jack/John Jack/Gwen Jack/Ianto
These are the three people whose relationships with Jack are addressed in KKBB. All of them are or have been in love with Jack, but their relationships are very different. One of the ways they differ is in the levels of loyalty between the characters. Not fidelity, although that is sometimes a related issue, but loyalty. How far do they feel they can trust each other to be true to the ground rules of their relationship?
Jack and John were lovers once, and judging from their behavior they once shared a very physical sexual relationship. It's clear in the opening scene they are still attracted to each other. But Jack is in no way still attracted to the lifestyle they once shared, as he makes it clear on the rooftop scene. John doesn't want to acknowledge the difference in Jack until he's forced to when he learns that Jack can't die, and even then he tries to downplay it.
Jack and John shared both an attraction and a physical relationship, but there is clearly no loyalty between them.
Again, this is not fidelity, as John demonstrates with his repeated offers of an orgy and/or attempts to seduce everything that catches his eye, but loyalty. They simply don't trust each other not to try to destroy each other when their backs are turned.
Jack and Gwen have always had an attraction but they have never had a sexual relationship. Jack is always concious of Gwen's relationship with her boyfriend Rhys. He is more respectful of that relationship than Gwen is, between lying to Rhys about things she doesn't have to lie to him about, shagging Owen, and making doe-eyes at Jack. Gwen asked Jack to show some interest in consumating their relationship when she told him she only accepted Rhys' proposal because "he was the only one who would have me." But Jack doesn't give her the slightest hint of interest at that point in time.
Jack and Gwen share an attraction but not a physical relationship. Jack is loyal to Gwen's boyfriend Rhys -- he refuses to be a homewrecker. (Is this one way that he differentiates the man he is now from his younger self?) We don't know if Gwen would be loyal to Jack or not, but her track record indicates otherwise.
Jack and Ianto share an attraction that dates back to the first episode. They appear to share a sexual relationship starting in the final third of the first series. Ianto is loyal to the bone with his lovers, as he demonstrated in spectacular fashion in Cyberwoman. Whether he was also faithful to her is a question that keeps fanfic writers up late at night, but he was clearly loyal to ner. But in the first series Jack denies that Ianto and he have enough of a relationship to be loyal to, both explicitly in Captain Jack Harkness ("There's no one.") and implicitly by running off chasing after another man without warning Ianto ahead of itme.
There's an interesting hint that Ianto has been loyal to the memory of how Jack did things on the extranet, where in an email exchange with Gwen he apologizes for objecting to something she did simply because it was not the way Jack would have done it.
It's no surprise that all of Ianto's non-work related questions for Jack deal explicitly with loyalty. When Jack says that he's "found his Doctor" Ianto asks, "Are you going back to him?" Jack looks down (Have we ever seen Jack look down before?), locks eyes with Ianto. and answers, "I came back for you." The camera pans straight back to Ianto, then straight back to Jack as if they were the only two people in the room. Only then does Jack remember that there are other people present, takes a breath, and amends it to, "All of you."
That's enough to win back a degree of Ianto's loyalty. When Jack once again goes haring off after another man, Ianto gives chase. And when the others slam Jack for being so inconsiderate, it's Ianto who defends Jack. "It's more fun when he's around though."
When he meets John, Ianto is the last to lower his gun. Fandom seems convinced this act is out of jealousy, but I'm not sure that there isn't a simpler explanation. The first series showed that Ianto was better than the others at reading Jack's body language. It could be that he's the only one who has picked up on Jack's cues that John is a dangerous snake in the grass who should under no circumstances be trusted.
Then Ianto wants to know "In what way" Jack and John used to be partners, although he must suspect, as John confirms, "In every way. And then some."
And then we have the lovely office scene, where in a typically subtext-laden approach, Ianto asks Jack his intentions. Here's my interpretation of that scene:
JACK: Oh yeah, I love that office-y feel. I always get excited in these places. To me they're exotic. Office romances... Photocopying your butt, well maybe not your butt, although whilst we're here why don't we photo ... (You are more exotic to me than John. Want to pick up where we left off? Want my ass right now?)
IANTO: The rift was active. These coordinates, approximately 200 feet above ground. That means this floor or the roof. (Not on your life. Now let's get back to work.)
Jack: How are you, Ianto? (Okay, let's see if I have a chance with you again.)
Ianto: All the better for having you back, sir. (I'm glad you're back but don't push it.)
Jack: Can we maybe drop the sir now? I mean while I was away I was thinking, (I spent a year in Hell, chained up, filthy, tortured, repeatedly murdered. All I wanted was to be between your clean sheets lying in your arms.)
you know maybe once this is all done, dinner ... movie? (Let's start over and do this properly.)
Ianto: Are you asking me out on a date? (Are you asking me to be your Official Boyfriend? Not just the office totty?)
Jack: interested?
Ianto: Well ... as long as it's not in an office. Some fetishes should be kept to yourself. (Okay, you’ve got a shot, but defenses are still at maximum. None of this 'part-time shag business. I expect you to do this properly.)
Jack: Looks like we'll have to check every drawer, bin and plant pot. (I'll cross every "t", dot every "i", and work through every step on your "Perfect Official Boyfriend" checklist.)
Ianto: Right. (Yes!)
Ok, I'll do this floor. Don't want you getting over excited. (Forget you, I don't want me getting overexcited and tearing your clothes off.)
Why don't you check the roof? You're good on roofs. (Give me a moment to cool down, okay?)
Jack? Why are we helping him? (Jack, why are you showing him more loyalty than you've ever shown me? What's he got over me? Don't I deserve some loyalty from you?)
Jack: He’s a reminder of my past. I want him gone. (I don't want to be the man I used to be when I'm around you. I don't even want to remember that I used to be anything like him. You are so totally different to me I want to segragate the two of you , the two of me, completely.)
By the way, was that a yes? (Please?, I've never felt this nervous before.)
Ianto: Yes... yeah. (Now get out of here before I set a bad example and start behaving like a less-than-proper boyfriend.)
It's interesting that while John flirts the most with Toshiko, Ianto is the only one he doesn't hurt or try to kill.
A bit later we have the autopsy room scene, where John has to face the fact of Jack's immortality. Among his other defensive posturings, he offers to have an orgy with Jack and the others. He's made this offer before, and Ianto has always rolled his eyes at it. This time Ianto seriously considers it, then takes a long look at Jack.
Fandom seems to think that Ianto is attracted to John and is seriously considering his offer. I doubt Ianto would seriously consider a fun romp with someone who had just murdered Jack and tried to kill the others. Ianto's mile-wide protective streak would nix that thought. I think the difference lies in what happened in the office scene. Jack has offered Ianto the position of Official Boyfriend of Jack Harkness, and Ianto has conditionally accepted it. But Ianto hasn't had time to think about what the Official Boyfriend role entails. Watching Jack flirt with other people? Watching Jack shag other people? Taking part in group sex with Jack? What are the rules of their relationship going to be? He knows what they are between a turn-of-the-21st Century man and a woman, but how are they going to define being loyal to each other when one of them is a young Welshman and the other an omnisexual immortal from the far future? This is something Ianto has to consider now.
Finally we get to the most disturbing scene in the episode for Jack/Ianto shippers. I'm not talking about the Jack/Gwen scene, but the Gwen/Ianto scene. When she thinks she has to jump into the Rift, Gwen says to Ianto, "Tell Jack. Tell Jack I...." Gwen and Ianto are both aware of the other's feelings for Jack. Ianto now has to consider if Jack and Gwen might ever act on those feelings from the perspective of Jack's Official Boyfriend. And what does he do? He tells Gwen, "Remind me never to get on your bad side." I'm not sure, but it sounds like what he means is, "If you want to shag Jack I won't interfere."
All in all, they did a lot of interesting setup work in this episode.
Part 1: Review
Part 3: Themes