“The plan?” Sarah half asks, focusing intently on her new prosthetic limb, watching the way her metallic fingers curl and flex. “Simple. Go back in time and warn my world of the incoming meteorites.”

“And that’s all you intend to do with the Deckkernator?” you ask.

“Well, once that calamity is dealt with, I intend to use the technology to revolutionise space travel and visit a few other timelines.”

You take in a sharp inhalation of breath. Sarah doesn’t notice, still fixated on her arm. “I don’t think that’s a very good idea…”

Too quiet. Sarah doesn’t even look up.

“Sarah,” you try again, a little more firmly. Now she does glance at you. “I think you should leave the Deckkernator with me.”

“Why?” Sarah looks genuinely surprised. “This tech would change everything in my time. It would allow us to go extra-solar. We could colonise half the galaxy overnight. This might even be what allows humanity to go galactic in your time.”

“But this wasn’t how we went galactic,” you try to explain. “We didn’t get a shortcut. We made a million tiny steps that made up a big leap. And messing with other timelines as well? I’m just worried the people of your time won’t be ready for this.”

“And I suppose you think people of your time would be?” Sarah snaps.

You open your mouth to disagree, but then stop yourself. Isn’t that exactly what you think? Isn’t giving the Flame Tablet equations to your time even more risky than giving Sarah’s time the Deckkernator? They may be 2000 years before yours, but that doesn’t make them savages. Perhaps you need to trust Sarah’s humanity just as you are trusting yours.

“Alright. Just… be careful with it.”

“Yeah, yeah, I know,” brushes off Sarah. “I’ll see you in the future,” she grins, then fires a Portal into existence.

I really hope I do, you think.

“Amelia! Where’s the bottle?”

“Just warming it up now!”

You turn your attention back to the complicated array of dials and buttons adorning the front of the microwave. Now… which ones did Tegan press when she did this? You think it was that one. And then this one. And then she turned the dial twelve clicks, and… wait, 60 seconds? That would mean… volume of milk, heat capacity of the container and fluid, assume an efficiency of around 80%… lukewarm milk? What baby wants that? You crank the dial up to fourteen, and exactly 70 seconds later, you cradle one delightfully warm bottle of milk.

“Ah, thank you,” smiles Tegan when you present your newly-collected trophy. Little Rosebud coos excitedly when she sees you, reaching greedily for her meal. Tegan bounces her gently on her hip as she gulps down the milk, gurgling in bliss.

“Ma! Draco is trying to feed Kaa, but it’s my turn!”

“Mum! You said I could do it because I missed last time - plus Liz got to feed the gators this morning!”

Seamlessly, you and Tegan slip into your familiar roles, consoling Draco (“You can feed the gators next time!”) while encouraging Liz to “Let your brother help you out a little”. The morning passes in a blur as the Keller-Keegan household (or more accurately, spaceship) feeds and cleans the reptilian enclosures, helps Tegan transport the latest rescue (a duck-billed feathered serpent) to a newly prepared pen, and settles down (as much as the kids ever do) for a few hours of tutoring with you. When the children are let out for a break, excitedly cheering upon hearing the news that Aunty Carmen is coming over for dinner, you’re even able to steal some time to work a little more on your latest line of inquiry: fourteenth-dimensional surfaces. Dimensions twelve and thirteen were simple enough for you, but fourteen is presenting quite the fascinating challenge.

However, your concentration is broken when you hear the news filter in from the tachyon in the next room over.

“…we remember those 1.2 billion souls tragically lost to the Perseid-7 Grand Implosion. On the fourth anniversary of what is undoubtedly the largest preventable loss of life in our time, the Galactic Committee on Dangerous Technologies has issued a statement reminding the galaxy of the risk of such technology in the wrong hands, and reiterates its commitment to ensure all such projects are equipped with the necessary measures to be used for the good of all. Here’s Bill with more…”

Unconsciously, your feet have taken you from your desk and towards the tachyon, turning it up to listen intently to the news reporter recounting the devastation caused by one madman with a mathematical equation. A mathematical equation you gave to the galaxy.

There were some who immediately saw the monetary value of such an equation and rushed to patent new warp engines. Others attempted to wipe it from existence, purging their solar servers of its stain. Still others pushed to implement it galaxy-wide, so no one was excluded from space travel by virtue of their wallet.

There were a lot of discussions and arguments in those early months, and a great number of mistakes, but eventually the galaxy did what the galaxy always does: it settled down. Conventions were introduced, policies were agreed upon, safeguards were created. The knowledge you shared still isn’t as free as you would have liked it to be, but it isn’t as censored as it could have been either. And that’s progress, at least.

From behind you, warm arms envelop you in an embrace. “Are you okay?” mumbles Tegan into your neck. You take a moment to close your eyes and snuggle into your wife’s warmth, feeling the solidity of her conviction to you. Of your conviction to each other.

You turn off the tachyon and swivel around to embrace Tegan properly.

“How could I be anything but?”