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“CHEMISTRY – ACE'S EXPLOSIVE ORIGIN”

Nitro-9 with a spark of heart!

Sophie Aldred steps into the author’s chair to pen Chemistry, her contribution to Origin Stories—a short but satisfying exploration of Ace’s formative years. There’s something immediately charming and authentic about this story: who better to write Ace’s backstory than Aldred herself? Her deep familiarity with the character shines through, presenting a believable teenage Ace—intelligent, impulsive, and brimming with untapped potential.

Set in Ace's school years, the story focuses on her growing obsession with chemistry, particularly the kinds of chemistry that go boom. Aldred uses the story to give us the origins of Nitro-9 and Ace's iconic bomber jacket, but more than that, she paints a strong internal portrait of a headstrong, morally principled girl with a real spark. Ace’s refusal to dob in her teacher after getting caught with explosives—even at personal cost—rings true for the girl we’d later see travelling time and space with the Doctor.

A DOCTOR IN THE CLASSROOM

A highlight of Chemistry is the mysterious appearance of Ace’s new chemistry teacher, who seems a little too quirky and wise to be entirely ordinary. Sharp readers will begin to suspect this might be the Doctor, and sure enough, she returns at the end and is revealed as the Thirteenth incarnation. It’s a lovely twist that ties together Ace’s past and future—and slyly acknowledges The Power of the Doctor, where Thirteen and Ace reunite on screen. That little moment of circularity adds unexpected weight to what could have been a simple prequel tale.

The story smartly avoids laying things on too thick—it never confirms outright that this teacher is the Doctor until the very end, and Thirteen’s brief appearance doesn’t overshadow Ace’s journey.

THE GOOD STUFF STICKS

Aldred's writing voice suits Ace perfectly: her teenage frustrations, moral compass, and rebellious streak all feel honest rather than exaggerated. The inner monologue captures the character’s mixture of righteous energy and scientific curiosity. Even when she’s making dodgy decisions—like stealing chemicals to whip up her first batch of Nitro-9—Ace remains sympathetic. She even experiences guilt and wants to return the chemicals before being caught, showing the beginnings of the moral compass that will define her TARDIS-era self.

The story’s most emotionally satisfying aspect is how Ace begins to understand that her abilities make her stand out—that being “normal” is not something she should aspire to. That message lands well without feeling like an after-school special.

A FEW DUD NOTES IN THE MIX

Unfortunately, not everything in Chemistry bonds as smoothly as its title implies. For a story so deeply personal, it’s oddly lacking in supporting character interaction. There are no real dialogue exchanges with friends, teachers, or classmates—so much of the story is told through internal reflection. As a result, the world around Ace feels a little flat until the closing scenes with the Doctor.

And then there’s the alien. In a rather sudden genre-shift, it’s revealed that Ace’s headmaster is a shape-shifting alien monster who tries to eat her. It feels like a strange third-act twist dropped in to add a dash of Doctor Who-style danger, but instead of enhancing the drama, it detracts from the more grounded coming-of-age story that was developing nicely. The monster’s presence is too brief and too underdeveloped to be scary or meaningful.

Worse still, Chemistry concludes with a memory wipe. Yes, another one. It’s a trope that’s been done to death across Doctor Who spin-off fiction, and here it feels like a cheap narrative reset button, robbing Ace of some of the emotional weight the story had worked to earn.

FROM PERIVALE TO THE STARS

Still, this is an origin story that works more often than not. Aldred doesn’t try to write Ace as a “proto-companion,” nor does she indulge in clumsy foreshadowing. Instead, she captures a snapshot of a young girl who is already smart, brave, and flawed, and who, in hindsight, was always destined for something more.

If anything, Chemistry makes a strong argument for Aldred to return to writing for Ace in a larger format. She gets her character better than almost anyone else—and when she's not being eaten by aliens, Ace shines brightly here.

📝THE BOTTOM LINE: 7/10

Chemistry is a warm, witty, and smartly observed coming-of-age story for Ace, written with heart and insight by the woman who knows her best. While a clunky alien subplot and memory-wipe ending undermine the emotional momentum, there’s enough charm, character, and clarity of voice here to make this a standout from the Origin Stories collection.