*** Author's Note ***

Towel Day Prompt: "Would it save you a lot of time if I just gave up and went mad now?" ― Douglas Adams, The Hitchhiker's Guide to the Galaxy

Love is by far the most vicious motivator. If he's said it once, he's said it a thousand times. And it has proven true time and time again.

A prime example is the scene unfolding in the sitting room of 221b Baker Street.

Random has only just completed what Sherlock is sure must be a very impressive rugby style tackle, and is now alternately taking swings and screaming at Lestrade.

Lestrade. Detective Inspector Lestrade. Who, it turns out, is an alien. Which shouldn't be surprising, all things considered. But it is. It's shocking. Sherlock had no idea. He never suspected Lestrade to be anything more than a passable detective with an intelligence marginally above the abysmal average of his peers. He supposes that should have been his first hint that something was amiss.

He considers himself a progressive thinker. Even accepts the potential for multiple, infinite, dimensions. And if someone had told him they'd found life on Mars in the form of primordial amoeba, well, that's just scientific advancement isn't it? He's even taken the time to learn the planets of the solar system - just let Pluto be a planet, for godsake - which now seems to be a moot point, and he mourns the time he lost devoted to the endeavor.

But no matter how enlightened his mind is, the concept of advanced life beyond the tiny corner of the universe he's most familiar with has him… Discombobulated.

Sherlock feels like the very foundation of his mind palace has been compromised. As if the doors and windows are disjointed and out of line. Like the walls are buckling and there are fissures opening up along the floorboards.

It's not the fact that there is a whole complex civilization just beyond the limits of what he understands, it's the fact that the civilization he does understand - or at least tries to, with John's help - is so very inconsequential. It troubles him more than he cares to admit that in a universe of infinite possibilities, the space he occupies is finite, soon to be extinct if the Grebulons have their say, with no other perpetuating hope.

He finds himself exasperated that the choice was made to allow the elimination of innumerable planet Earths. That an incalculable number of human lives ceased to be with nothing more than a few signatures.

Sherlock is aghast… No, appalled… Horrified that not only does his Earth of origin no longer exist, but he doesn't recall it happening. How is it possible that none of the seven billion people, from as many varying dimensions, ripped from their own realities and transplanted to this fabricated terrarium, noticed the change at all? He's long suspected the human race as a whole are idiots, and this confirms it. Even though he didn't see it either.

Then again, he did notice a change in his relationship with Mycroft. And with that recollection, he's overcome with grief. It lasts only a moment, and he schools his features, because he can't let anyone, let alone this version of Mycroft - not his Mycroft; he doubts this Mycroft played pirates with his own version of Sherlock when they were young - see that he's affected by the disadvantage of having a working flesh and blood human heart.

He hates this version of Mycroft. What he's done. What's been done to all of them. And he hates that he understands why Mycroft would opt to save some of humanity if he couldn't save all of it. He doesn't like it, thinks it's wrong on the most basic, fundamental level. But he understands. It makes more sense than… Just about everything else.

Human flight, for one. Or illegal alien laser drills. Or having one's entire personality, and all their memories, quirks, and the things that make them uniquely them, stored in a hard drive. Or an impending alien apocalypse.

Like the fact that the man who should be his brother - if tested they share all the same familial markers every combination of the two of them in any dimension would have shared, despite the fact that they don't actually share the same parents at all - is actually just a bureaucrat.

Or that men with two heads - who literally talk out of both sides of their mouths - sign treaties condemning entire races to death and turn their friends over to their enemies, all so they can afford big fancy spaceships. Which they land in the middle of the beloved duck pond in the park.

And what of the mysterious, moody man with the long coat and the imperious attitude? He thinks he knows more than everyone in the room, and he's always on that damned device. And yes, he sees how some people might draw comparisons; those people are idiots.

Then there's the problem of Random, who is dangerous, volatile, unpredictable, and Arthur's daughter, but not John's. Because even though they share a body now, they didn't way back then, so John had no input. The problem there is that Rosie is John's daughter, but John was using Arthur's body at the time, so she is also Arthur's daughter. That means they're sisters. Rosie has a sister. Sherlock admits freely he acts as a second parent to Rosie most days, but it's been nine years and he still doesn't really know what he's doing. And now there are two daughters to be vigilant over - and he's infinitely grateful that Random is an adult and can make her own choices.

But that problem is compounded by Gavin Lestrade. He's the one person Sherlock has trusted the longest, since he stopped trusting Mycroft years ago. Except, he's not even a person, and isn't that just an enormous betrayal of trust?

In contrast, John is a person. But, a person with one body and currently two minds, two distinct personalities struggling for control. He's sure Arthur is a decent enough man, but it's John Watson who is essential. John who he needs more than he needs air. John who he has loved for years, but never dared to hope for reciprocation. John who loves him back, who was brave enough to finally say the words, and who taught him he doesn't have to fly to soar. But John isn't just John right now. He's trying to be brave Captain Watson as he prepares to face space and aliens and all the things he only learned are true at the same time Sherlock did. And, he is also Arthur.

And it's Arthur Sherlock restrains when Random accuses Lestrade of promising her the universe and then sticking her with the check at a dump of a diner on a dump of a planet with beaches that are only okay.

It's also Arthur Sherlock pins to the floor when Lestrade explains that his leave was only a week long that time, but he got called back to Earth early because Sherlock and John were snooping around a top secret military base. Duty calls and all.

Below him, Arthur is tense with rage, cursing Lestrade and eyeing the laser drill.

Love truly is a vicious motivator.

So he's not sure what it means when Lestrade mentions, too casually - Random is apparently cried out, Mrs. Hudson and Rosie are attempting to comfort her - that upon returning to London from Baskerville he and Mycroft had started a still on-going dalliance, and it's John who has to restrain Sherlock when he dives for the laser drill.