School Reunion (Series 2, Episode 3) brings Sarah Jane Smith and K9 back into Doctor Who for the first time since the classic series, as the Tenth Doctor investigates a school where the pupils have been turned into a living supercomputer by the shapeshifting Krillitane. The post covers the episode’s alien plot, the Skasis Paradigm bargain Anthony Head’s headmaster offers the Doctor, and the emotional weight of Sarah Jane and Rose meeting as two companions the Doctor left behind.
The review rates the episode 4.5 out of 5, calling it a near-perfect blend of nostalgia and emotional heft anchored by Elisabeth Sladen and Anthony Head, and highlights K9’s sacrifice and Mickey Smith’s decision to finally join the TARDIS crew as the episode’s most memorable beats.
Some episodes are about a monster. This one’s about a goodbye that never happened. School Reunion has a perfectly good alien menace ticking along in the background, bat-winged body-snatchers running a comprehensive school, but that’s not what I’ll remember about it. What I’ll remember is a woman walking into a darkened classroom, recognizing an old blue box, and the floor dropping out from under the whole series. This is the most emotional hour Series 2 has given me so far, and it earns every bit of that.
Something’s Wrong at Deffry Vale
We open on the Doctor doing something I found genuinely funny: teaching. He’s gone undercover as physics master “John Smith” at Deffry Vale High School, where the pupils have turned alarmingly, unnaturally brilliant, and Rose is skulking around in a hairnet as a dinner lady, hating every second of it. It’s Mickey, back home and doing his own digging, who flagged the school in the first place, and I loved getting to watch the Doctor clearly relish being the cleverest person in a room full of teenagers. The culprits are the Krillitane, a nasty composite species that conquers other races and physically absorbs the bits it likes, so this generation sports leathery wings and a taste for children. Disguised as the teaching staff and led by the wonderfully oily new headmaster Mr Finch, played by Anthony Head at his most silkily sinister, they’ve been lacing the school chips with Krillitane oil to supercharge the kids’ brains. The children aren’t students, they’re a living supercomputer, being run flat out to crack something the Krillitane very badly want. It’s a strong, creepy premise, and Head is a superb foil: all charm and menace, practically the anti-Doctor in a headmaster’s suit.
And then she walks in. Sarah Jane Smith, investigative journalist, sniffing around the same story, steps into an empty classroom, finds the TARDIS parked in the corner, and Elisabeth Sladen plays that moment of recognition so beautifully I didn’t need to have seen a single frame of her original run to feel the weight of it. Here’s someone who travelled with the Doctor long ago, who he left behind and never went back for, standing face to face with a man wearing a stranger’s body but unmistakably him. Den of Geek made the case years later that this is the episode where the revived show finally admitted its companions have lives after the TARDIS, and I think that’s exactly right.
Two Companions Collide
The episode turns that reunion into its real subject. Sarah Jane’s hurt is raw and specific, because she waited, she says, she looked up at the sky, and she never quite managed to move on. Watching all this land on Rose is the masterstroke for me. Rose has spent these last few adventures glowing with the sheer joy of it all, from the apple grass of New Earth to the werewolf hunt through Tooth and Claw, secure in the idea that what she has with the Doctor is singular. Sarah Jane is living proof that it isn’t. The two of them circle each other with a jealousy that curdles into something like solidarity, trading barbs and then, gloriously, trading stories at the Doctor’s expense. It’s funny and it’s devastating in the same breath. The real gut-punch for me is Sarah Jane’s quiet certainty that she must have done something wrong, that she wasn’t enough for him to come back for, when the truth is simply that he couldn’t bear to stay and watch her grow old. The Doctor doesn’t have a good answer, because there isn’t one, and Tennant lets you watch him flinch from the question. There’s an old friend in the boot of her car too: K9, the robot dog, rusted and defunct and instantly, ridiculously lovable. The show knows exactly how much affection it’s trading on here, and it doesn’t overplay its hand.
The God-Maker’s Bargain
That question comes to a head when Finch reveals what all those child-powered calculations are actually for. The Skasis Paradigm, the “God-maker”, is the fundamental equation of the universe, and crack it and you can bend time, space, matter and life to your will. Here’s the cruel part: the Krillitane don’t want to fight the Doctor, they want to recruit him. Finch offers him a share of that godlike power, and dresses it up as the one temptation I don’t think this Doctor can easily resist: the chance to stop losing people. To reverse the pain, undo the deaths, maybe even bring back everything the Time War took from him. For a moment he wavers, and it’s genuinely terrifying, because I’ve felt the size of that loss ever since the regeneration in The Parting of the Ways. It’s Sarah Jane who talks him down, and she does it with the hardest wisdom the show has offered yet: everything has its time, and everything ends. Pain and loss aren’t a flaw in a life well lived, they’re the price of it, and a universe frozen into permanence just to spare the Doctor his grief wouldn’t be worth having. He lets the power go.
A Tin Dog’s Last Stand
The Krillitane are undone by their own oil, and it’s K9 who does it, trundling the battered old dog into the danger zone to detonate the barrels and take the monsters with him, sacrificing himself to save a hall full of kids. It’s a hero’s death for a tin dog, and it stung more than I expected. But the Doctor, being the Doctor, has a parting gift: he quietly builds Sarah Jane a brand new K9 to take home so she doesn’t have to be alone. It’s the going-back he never managed the first time, offered at last. Mickey’s arc quietly grows up here too. He’s the one who called the Doctor in, and yet he spends the episode on the sidelines once more, until he clocks the rusted robot dog in the boot and has a rueful little epiphany: to this crew, he’s the tin dog. The spare part. The one who stays home and does the legwork while everyone else runs toward the danger. Ever since his bruising, sidelined turn back in Boom Town he’s been chafing at exactly that role, and this time he finally does something about it. He asks to come along, and when the Doctor says yes, it plays less like a reward than like Mickey quietly refusing to be the one who gets left behind.
What it leaves me with is Rose learning the truth, that she isn’t the first and one day she won’t be the last, and the episode is honest that the knowledge hurts. It leaves the curse of the Time Lord said out loud, because he can give a companion the rest of their life and never give them the rest of his. It leaves “everything has its time, and everything ends”, which is the show’s whole philosophy handed over by a former companion, the thing that ends up saving him from the God-maker’s bargain. It leaves Mickey in the box, tired of minding the home front and finally asking for more than that. And it leaves a goodbye done properly this time, since Sarah Jane chooses not to travel again but goes at peace with a new K9 beside her, which is the show quietly promising me that the Doctor’s departures don’t have to stay wounds forever. Doctor Who News’ review at the time called it one of the strongest scripts the show had done, and having watched it, I don’t disagree.
Rating: 4.5/5 – a near-perfect blend of nostalgia, character and genuine emotional heft, anchored by Elisabeth Sladen and a razor-sharp Anthony Head. The Krillitane plot is the least of it, and it barely matters. An undercover Doctor, a legend of a companion, a robot dog’s last stand, and a lesson in letting go. Mickey’s in the box now too. I can’t wait to see how that goes.