It never fails: Just when you've finally got a new man in your life, the old boyfriend turns up to cause trouble. Actually, David Tennant's guest spot on the Sarah Jane Adventures was remarkably innuendo-free.

This is how we know that Russell T. Davies is no longer really involved in running the Sarah Jane Adventures: if RTD had been in the mix, "The Wedding Of Sarah Jane" would have been laced with little references to the Doctor as Sarah Jane's former boyfriend, who's showing up to stop her wedding to the cute new guy, Peter. As it was, the episode was remarkably respectful to the former companion, repeating several times that the reason she'd never gotten a bloke was because she was too busy saving the world herself, and she wasn't sure if any guy could deal with her weird life. Which is way better than the explanation RTD wrote: that she was still hung up on Tom Baker all these decades later.

So in "The Wedding Of Sarah Jane," she falls in love with a guy remarkably quickly and then agrees to marry him like a shot... so of course you know it's an evil scheme. The nice touch is that Peter Dalton isn't actually evil himself, or alien for that matter. He's just a pawn, who happens to be genuinely a good match for Sarah Jane. If they'd met under other circumstances, they might have gotten together normally, without any of this "fiendish trap" nonsense.

But the fact that Sarah Jane feels she can't tell Peter about her real life of hanging out with robot dogs sort of raises a larger point that the RTD version of Doctor Who has skirted around a few times: At this point, after all these alien attacks, there are just two kinds of people left: The ones who know all about aliens and are completely obsessed with learning all about them... and morons. So if Sarah Jane feels like she ought to date a man who can deal with her alien-fighting lifestyle, then her dating pool ought to be enormous. I guess this is a sort of suspension of disbelief thing, except that Doctor Who has gone out of its way to poke holes in it a few times.

In any case, the wedding episode was fun — and completely a rehash of stuff we've seen before, of course. Every time we see the Trickster, he gets a bit less interesting. His first outing, where he changed history so Sarah Jane died as a small girl, was fantastic — but since then, he's been stuck doing variations on a theme. Plus some homages: This time, we get a bit of the "Buffy's mom dates evil Jack Ritter" episode, a bit of every wedding episode ever, and a bit of the final episode of Sapphire And Steel, with the being trapped in the house that's floating outside of time and space.

Presumably a lot of regular Doctor Who viewers tuned into this one for the Tennant appearance, so I'll just say that the Sarah Jane Adventures is sometimes a bit better than this story, which felt a bit motionless, especially in its second half. At its best, the more young-kid-friendly Who spinoff is fast-paced, fun, a bit silly, and very reminiscent of classic 1960s and 1970s Who, with implacable monsters, young companions, and dilemmas that are soluble with large amounts of pluck. (Especially in its first season, the show ruled, and it's been making a major comeback this year after a weak second season.)

I never actually thought I'd say this, but I think a bit more RTD sentimentality could have served this story quite well — it had the Murray Gold "woooooooo" sad music for large chunks of the second episode, but it never quite felt like it got to the emotional root of what was going on — either the kids feeling left out or worried because Sarah Jane had someone new in her life, or Sarah Jane realizing that it's all a trap, and she can't really have romantic love as well as everything else she's built in her life. Somehow, the episode kept skimming over the really interesting bits - and Sarah Jane and the Doctor never quite manage to have a real conversation. I was sort of hoping they could have a chat about how she's becoming more and more like a human version of the Doctor, and what that's meant to her relationships. I know it's a show for little kids, but little kids like to know that these characters are real people, with feelings.

Other stuff: We got yet another otherworldly creature giving a speech about how the Doctor is fire and ice and chocolate and nougat and so on. It was really nice to see K-9 back in his element, and especially interacting with the Doctor once again. K-9's little rivalry with Mr. Smith is fun as well. I'm glad the Doctor realizes how terrific those kids are, and once again Clyde gets to be the hero, which makes me happy. And I guess it's good that Sarah Jane's arch-enemy rates the Doctor's respect — since the Trickster mostly seems like a very second-string villain at best, it's nice that the Doctor didn't just dismiss him.

Oh, and most of all, we're getting Sarah Jane built up as the defender of the Earth, without whom we're all toast. The first time around, there was a concrete reason for that — an asteroid on a collision course with the planet, that Sarah Jane needed to be there to deflect. But now, it's just more vague and all-encompassing. Without Sarah Jane, the aliens will just run rampant. It makes you wonder quite how ineffectual U.N.I.T. is these days.