In the entire history of television, has anyone else ever done a body-swap plot for drama instead of humour? It was an inspired choice by the Xenabods and it just goes to show what can be done involving a simple story and characters we’re emotionally invested in. No other bells or whistles required.

At its heart Intimate Stranger  is about a love/hate triangle. Callisto hates Xena for killing the family she loved, Gabrielle hates Callisto for killing the man she loved, Xena hates herself (as per usual), as well as Callisto for hurting the woman she loves when she killed Gabrielle’s husband. So that’s a whole lotta death, hate and love going around that prickly trio, and lots and lots of raw angst to deal with.

All other characters are mere asides – a neutered, patsy Ares, who discovers yet again he’s being played by his latest powerful female champion; Joxer the eye-rolling, fall-guy comic relief to remind us to loosen our death-grips on furniture and/or family members once in a while; Hades, to remind us why acting class should be compulsory, and Cyrene, the home-and-hearth jeopardy character to pluck at the conscience and fears in Xena.

The beating heart of Intimate Stranger  really is intimate. It blurs the line between our favourite heroes and villain, pondering who is good and who is not, and asks us to question even where the line is. Is Xena a murderer because she let Callisto die? How much blame should Callisto bear for her crimes if Xena made her what she is? Should Xena have given Callisto a second chance as Hercules did for her? Is it still a murder if one were to kill someone who is already dead?

This philosophical angst is helped by having a pair of impressive actresses in Lucy Lawless and Hudson Leick, who pull off an incredibly demanding task of inhabiting each others’ roles. They must caricature each other, which is both daunting and potentially a little insulting. No one likes to be mocked for their acting style after all – so they had to be sure they were invoking the essence of the other but not parodying her character.

Lucy had the slightly easier job, for Callisto’s famous tics and shrieks are as memorable as they are exaggerated. A curled finger here, a liberal display of gum-baring rows of white teeth there, a sly smarmy delivery, a jerky head, and, bam, Callisto is in the room. Lucy truly made me believe – and many times I forgot it was Lucy not Hudson playing Callisto, despite the clear evidence before my eyes. Now that is a masterful feat.

Hudson meanwhile had to make like a mannish statue. She had to still her movements, swap the sing-song speech for a near monotone, practice being slow to the point of zen in her mannerisms and neck movements (no hunching over, Gollum style), walk as though she had weights in her boots, lead with her shoulders and, whenever possible, gaze at Gabrielle. It’s a much harder job to play the stiller and less eccentric of the characters, however Hudson, too, made me believe.

Without these two women’s acting chops, the episode simply would not have been possible. So I wonder: which came first? Did they decide to ask the women to impersonate each other and see if it was believable, or, with great faith in their actresses, did they just naturally assume they’d be able to knock it out of the park and presented the script to them as fait accomplice?

Either way they got very lucky – for two reasons. The first being the obvious end result of a convincing body swap, and the second because of Lucy’s real-life broken pelvis injury, which meant Hudson could literally shoulder Lucy’s burden throughout the next episode by remaining on as Xena.

But back to our angsty little trio. This episode is all about the guilt and buried issues of Return of Callisto. On the surface you’d immediately go, "Well hey it would have been impossible for Gabrielle to lose her husband during her honeymoon to some crazy blonde psycho and never mention it again. Of course there’s some emotional dealin’ to be done."

Yes, well, you’d think that.

Which brings me to Perdicus. Sorry, I should have warned y’all first. This story contains occasional references to dead beaux of the boy-band variety.

I’ve said it before and I’ll say it again – that farm boy had only one purpose and one purpose alone in Xena. In Return of Callisto he was brought in to establish that the once teen groupie Gabrielle is now officially an adult, or to be blunt, emotionally and sexually mature, and therefore old enough to find a lover now or in the future without anyone fretting over whether to call the authorities.

But even though Perdicus was only ever a plot device akin to giving Gabrielle ID to flash at the bar, his death would have still made a powerful impact on the young bard. To ignore it would have strained credibility beyond belief.

So, no, they didn’t ignore her loss, but they did somehow manage to make it all about Xena. If I were Ren, I’d be thinking "Hey, how does Callisto killing my husband become Xena’s story?"

Perhaps it was because they didn’t want to hang a lantern on how the loss of her husband reminds us all of her perfunctory wedding to the narcissistic bloke who wooed her five seconds after meeting her again with those self-absorbed words of ‘adoration’: "I need you."

But actually the answer is more likely that Xena’s is the more interesting story. And Callisto and Xena squaring off again over all that guilt rage with those thinly veiled entendres flying, well, hey, pass the popcorn folks.

Gotta love those two together. In whoever’s bodies they’re inhabiting, they’re a sight to behold. Callisto’s flirtatious one-liners of "Oh how I’ve missed you … it makes me appreciate what we had" were matched by her taunts "Oh keep telling yourself that dear, maybe one day you’ll believe it."

For a dead woman, she’s remarkably unchanged. Her goals are the same. Her agenda barely has an addendum to it, beyond "Item 3, Maim Argo". This makes Ares particularly stupid – as Callisto has never been shy about what she wants in life or death (the ongoing torment of Xena). And yet he just accepts she’ll go along with his plans. Sure, buddy, sure.

The pair also go at it like rabbits, much to everyone’s astonishment at the time the ep first aired. But if you’ve ever seen the standoffish body language bordering on repulsion Callisto has with all the males in her universe, it’s fairly easy to work out that she’s doing the wild thing with the God of War just to piss off Xena about liberties taken with her body when she finds out about it later.

Did I mention Ares was particularly stupid this episode?

Which reminds me – check out the Xenabods’ naughty juxtaposition between those two dropping out of frame for some horizontal action, and Gabrielle thrusting her pointy stick up in the air only a beat later. I guess they didn’t have trains and tunnels back then, right?

While Callisto’s character was unchanged, Gabrielle got to reprise her portrayal of red-eyed outraged agony from Return of Callisto. The blonde psycho has worked out that, like Pavlov’s dog, one need only say the P-word to unleash Gabrielle’s fury. And Callisto gets a special sick little thrill by saying Perdicus’s name constantly and invoking memories of his death at will.

While it’s good to see they’re not glossing over the rawness of all this for Gabrielle, they never really did resolve anything for her. She is as tormented at the start of this episode as she is at the end.

I’ll be kind and say this explains why she didn’t question aloud the fact her dearest friend had morphed into something from the Exorcist. Xena is many things but cruel isn’t one of them. And while Gabs’ face showed a cascade of emotions, hurt, questioning, confusion – she never spoke up and said "OK who are you and what have you done with Xena." This is the time of ancient Gods after all, all things are possible, and Gabrielle is smart enough to have at least considered the possibility this wasn’t her friend at all.

The only character who did change throughout, and put some of her demons to rest was Xena. She has worn her guilt around her like a great cloak, and we find out all this time she has also been carrying with her the burden of Callisto’s crimes, too.

When she finally says she will no longer do this – "I’ve got my own past to deal with, but I’m not taking the weight of your crimes any more" – and that Callisto must take responsibility for them (with Callisto’s mother echoing the sentiment), it is as though Xena’s been waiting to exhale for years. And she finally does.

Yet I am struck by the fact she wouldn’t have done this voluntarily, doing so now just to keep Callisto in Tartarus, even though it was within her power to drop that burden all along. And so we’re left to believe she actually likes her great guilty cloak – it’s what she knows and what she thinks she deserves. So she shoulders it again at the end of the episode, albeit a little lighter, with Callisto’s burdens gone.

Then we see Xena must remain in Callisto’s body. If it wasn’t for the fact this is just a rewrite because of Lucy’s injury, it’d be tempting to see the outcome as a beautifully crafted piece of poetic justice – a punishment she would happily pay – that is, being forced to wear the face of the killer she felt she created.

Of course one woman’s "fair" punishment is another woman’s torture. And the look on Gabrielle’s face says it all. "Oh Xena" she whispers.

Oh Xena, indeed.

I was really impressed throughout this entire episode at how perfect Gabrielle’s reactions were to seeing Xena inside Callisto’s body. Before she speaks, each time she pauses and almost swallows and continues. Joxer’s responses may have been really funny – a "reflex" as he explains it; Gabrielle’s were a silent pained agony. And in the final scene, realising she may have to look at Xena forever wearing the body of her husband’s killer, it’s like all her last defences are crumbling.

Which all led to the most peculiar line of the entire episode –Xena tells Gabrielle not to see the body of the woman she hates but that of the man she loves. Um, what the?

Xena just asked Gabrielle to look at her body and see Perdicus?! I am wondering if the line was initially something else about seeing the friend she loves, and they changed it due to the high level of the subtext. Whatever the reason, it’s simply the oddest thing to ever say to someone. I think Gabrielle’s confusion was matched by Renee’s as well.

That one line aside, the episode was a fine thing – trim, taut and terrific. It would have been enhanced if Gabrielle had some resolution for her loss, or Hades learned how to say Callisto’s name correctly, but all in all it was a moving episode, oozing with drama and pathos.

Now who’d have thought they’d ever hear that said about a body swap plot on a TV show!