Welcome to the highest-rated episode in Xena history. When it first aired, bosses Rob Tapert et al were all scrambling to figure out why this was so. Their reasons were hilarious. In some interviews they speculated it was pure Velasca power, and in others the assumption was that the Callisto-Velasca superhero smack-down caused Nielsen meters to spike.

Uh, sure guys.

As any fan could have told the powers that be, it was a lot simpler than that. Xena and Gabrielle kissed in the previous episode and everyone was dying to know what they’d do next. Would they talk about it? Maybe do it again? Or find some hunky hunks to prove their straight creds with?

Well the answer was no, no and no. Not that it matters.

A Necessary Evil was a rewarding episode in many ways – and, sorry Rob et al, that was in spite of Velasca not because of her.

I have nothing against a bit of panto’ villainy, and watching Velasca stomp around like Robo Barbie while calling for Gabrielle, was pretty funny. "You can’t hide from a God, Gabrielle," she shrieked at one point, even as Gabrielle was doing exactly that. Yup – a laff a minute to be sure.

But Velasca was a bit too over-the-top high-camp for me, and her antics detracted from some really incredible scenes, making the episode more cartoony than it should have been. But that’s just a personal preference. I know more than a few pro-Velasca pundits who’d declare those fightin’ words.

What I did love in this episode was what I’ll call the Callisto Dynamic. But first a disclaimer: Yes it is absurdly silly and improbable that Xena would unleash a nutty psychopath who killed Xena’s best friend’s husband (the same best friend still having nightmares about said killer) and declare this to be the only possible solution for containing a second evil psycho missy. But without Callisto it would have made for a far less entertaining episode. So I’ll just insert a formal arched-eyebrow protest and move on.

We always knew the rabid blondie loved to toy with Xena. Now that the big X has almost entirely stopped responding to her taunting, Callisto’s focusing more on her game of Bard Baiting in this episode. If you can’t mess with Xena, then mess with the one she cares about. The scenes with Gabrielle and Callisto or all three of them together are simply dynamite. There’s always something going on, and Hudson is an absolute master of milking a scene.

In fact Callisto’s most creative moment comes when we see her for the first time and she picks up a rat. She’s eyeballing it, talking to it – and watch what she does next. Yes, folks, she starts windmilling the critter’s whiskers, like she’s winding up the propeller on a toy plane. Apologies to the rat, but it was a genius moment from Hudson, showing her crazed state in just a single quirky gesture.

I mentioned this episode has powerful scenes, and the first is Xena’s speech to the village, cataloguing her various crimes. I notice for all the power of her words, she never once said sorry. Interesting. Perhaps if that little display had been about her and she was on some personal penitence kick she might have said sorry, but it wasn’t about her at all.

I notice she looked directly at Callisto the entire time – that’s hugely challenging if you’re a guilt-bunny like Xena. But that action gives the impression Xena’s already laid to rest these particular demons and this is all just an exercise in appeasing Callisto. (Massive points by the way for not treating the audience as stupid and spelling this out to us – we all knew why she was giving that speech, even though no one, at any time, said so.)

I loved the look on Callisto’s face throughout – she looked stricken even as she finally satisfied whatever burning urge that speech represented to her. It had to have been hell for Hudson to do this with the wind whipping fiercely all around her like that. (Oddly Xena’s hair stays perfectly straight. Well she is Xena.) Anyway, it was an amazing moment, and is just one of those scenes they toss in for us every now and then as though to remind us Xena is no mere ordinary show. It really rises above when you least expect it.

I had to laugh at the reaction to the villagers of the astonishing confessions of a mass murderer. They looked at Xena as though to say: "Well that’s very interesting dear, but this laundry won’t wash itself."

The one thing that almost undid that scene was the episode’s second powerful scene – Callisto and Gabrielle’s game of truth around the fire. Gabrielle asks Callisto what she felt when she heard Xena’s confession in Cirra.

First time I heard the question, I held my breath. Incredible – finally someone asking what we all wanted to know. What, oh what, will be the next words from mad-dog Callisto?

And she replies …. "I never feel anything. Just bits and pieces…"

Damn the woman.

Well either she’s lying - and despite her many flaws dishonesty isn’t one of them - or her face was. Because Callisto was showing some incredibly detailed interplays of emotion across her face in that village. The pain was real and it was raw. It would have been nice if the script had backed that up - such as Callisto saying how Xena’s words brought back memories she’d long buried, or something else to explain what we saw on her face.

But oh the chills in her follow-up explanation to Gabrielle about why she is the way she is: "Think back to when you were a little girl and all your faith revolved around your mother and sister. …. Now kill them."

Wow. It’s like Callisto just reached out and slapped your cheek and said "That’s what being me feels like. Wanna feel it again? No? Tough. Whack."

Her counter-question of Gabrielle was, of course, fake in every sense – she had no interest in the time it took for Perdicus to die (she was there after all; she already knew) and she also, in my opinion, had no interest in asking it simply to make Gabrielle squirm.

It felt like she desperately wanted to shift the subject off her own uncomfortable past and before Gabrielle started getting too close to the bone. Callisto doesn’t like too much introspection. If she examines herself too long she may just have to admit she’s a bigger monster than the one she thinks she’s fighting and it contradicts the perfect world view she has of herself as a completely innocent victim in her life’s journey.

If Gabrielle had ignored the Perdicus question and instead asked Callisto another probing personal question, she may well have found herself on the pointy end of that sword Callisto was sharpening all night. Let’s face it, you probably shouldn’t try your luck with crazed narcissists. Luckily for Gabrielle’s health, she responded predictably in another fine display of outrage.

That’s not to say the Perdicus question didn’t also give Callisto a laugh – it wasn’t entirely a diversionary tactic. But in case you haven’t noticed, Callisto does like all her conversations to be entirely on her terms.

One last word on Callisto before I leave her to her toasty lava pit – have you noticed she’s had ample opportunities now to kill Xena and never once obliged?

At one point in this ep Xena virtually puts her chin over the point of Callisto’s sword as if daring her to make good all her threats. Callisto just smiles. She really doesn’t want to kill Xena in any way, shape or form. Not in battle. Not even for fun. Just not ever.

She does love playing with her, though – and her line "Why don’t you and I both eat (ambrosia), then we could be fighting each other for eternity" tells you everything you ever needed to know about her true motives. She just wants to be in Xena’s orbit – challenging her, forever. In her own twisted way it’s probably a form of devotion.

Which explains her attitude to Gabrielle. That’s just pure and simple jealousy over the fact the bard gets to spend all that time with the object of all her stalker fantasies. If Callisto hurts the bard, she gets two results – she antagonises Xena, and, as a bonus, she hurts the bard. *grin*. Perhaps Callisto is really not that complex after all.

In sum, if this episode has any theme it is obsession. Velasca’s obsession for power (and note, she can’t just stop at godhood. Now she wants a portfolio, too – specifically, the God of Chaos); Callisto’s obsession for Xena; Xena’s obsession for Gabrielle. OK, well that last one wasn’t a theme but it should have been!

A Necessary Evil was actually a good bridge between The Quest and the next episode A Day in The Life. It was the middle point in a very gentle and gradual evolution in the way Xena treats Gabrielle. In The Quest came the kiss – but as kisses go, it was more about a question being asked than a specifically romantic moment.

In A Necessary Evil, Xena acts like a woman who now knows the answer, and is thinking about what her next course is. She is even more protective of Gabrielle as if she has finally been given the right, or permission, to act this way. In A Day In the Life will come the flirting. But for right now – the Warrior Princess looks like she’s feeling her oats. And the bard ain’t complaining.

There were a few lovely interplays between the two – the smirk on Xena’s face as Gabrielle wants to know if an Amazon queen beats a Warrior Princess. I swear it looks like Xena is thinking of all the possible scenarios to test Gabrielle’s theory and not all of them seem entirely G-rated.

Finally, some technical nods – I loved the novel ways to sort out heroes and villains in this episode. The stunts were off the scale – the explosion that did in Xena’s shoulder in the camp had her flying high; the pole vault over Velasca was as funny as it was creative; and the trapeze-act in the final fight, where Xena saves Gabrielle on the world’s least-stable rope bridge, was great. On the minus side, the music verged from creepily interesting at the start of the episode to Scooby-Doo-style hijinks music in the end fight. A little over-the-top there - perhaps better suited to an audience entirely under age nine.

The people who add the atmospheric effects did a marvelous job – if you need proof, watch the ruins fight scene with the sound on mute and suddenly all the sets look cheap(er), and the actors seem to have been somehow Photoshopped into Power Rangers, complete with the arch villainess. (Insert evil cackle.) Who would’ve thunk a wind machine, amped up sound effects and hollering heroes could make such a difference.

The ending was in a word, sweet. It could have been all about C1 and C2 (Crazy and Crazier) toppling into the hair-frizzling pit, but they had to bring it back to Gabs and Xena. In particular, Gabrielle. She wants to forgive Callisto and move on.

She wants to believe Callisto still feels. Come to think of it, we all do. The enemies who feel nothing – aka Velasca or a thug of the week – are a lot less compelling than the ones undergoing torrents of emotion, trying to fight off their humanity even as they do their evil deeds.

It’s nice Gabrielle still believes in that shred of humanity in Callisto. It says more about the bard than Callisto – which explains the proud look on Xena’s face at the end.

In sum: this was a cool episode. It had heart, it had soul. And, yes, Rob, it even had a superhero smackdown.