SERPENT'S TOOTH

In the time before Sherrinford, Mycroft had called his parents on average twice a month. He had made efforts to know their schedule, call when convenient, and never keep them on the phone for longer than they desired.

After Sherrinford, that stops.

He sees them during the visits to Eurus, visits that he cannot – dare not – escape; speaks with them during the calls arranging and confirming the details of transport, time, and location that make the visits possible. Nothing personal is discussed – they do not seek to know, and he lacks the courage to venture and be rebuffed.

He is not a child. He knows that anger does not mean that love is absent. This… is not anger. He is not afraid, precisely. But he has distance enough now to calmly evaluate all his own weak spots – the soft places in desperate need of armor.

Caring is not an advantage.

They are enraged with him; and the fury ebbs and flows across the days of the month in relation to the visits to Sherrinford.

His own anger avails him nothing.

They did not listen when he was twelve, thirteen, fifteen, forty-five – they will not listen now, and likely never again. Not about Eurus.

"Alive?! For all these years? How is that even possible?!"

"What Uncle Rudy began ... I thought it best to continue."

"I'm not asking how you did it, idiot boy, I'm asking how could you?"

"I was trying to be kind."

"Kind?! You told us that our daughter was dead."

"Better that than tell you what she had become. I'm sorry."

"Whatever she became, whatever she is now, Mycroft ... she remains our daughter."

"And my sister."

"Then you should have done better."

"He did his best." Sherlock, surprisingly.

"Then he's very limited."

They have been silent on other topics, but he is not unintelligent enough to believe that silence to him means they have abandoned their foolish hopes of Eurus's release; a throwaway comment to Sherlock during one of the car rides back to London from the helicopter landing pad on the mainland makes that clear. He is briefly grateful for continuing the surveillance in his own vehicles.

It was why Uncle Rudi manufactured and maintained the ruse of Eurus's death in the first place. Four months without incident in the second facility, and they had begun to talk of bringing her home.

It is why Mycroft keeps an envelope, heavy with discs, marked by year and incident. It sits in the crib that once was his, in the one room of his home where few would find it – plain sight, and yet so very hidden. Precisely because no one cares enough to look.

He may not have the luxury of maintaining this last protection for very much longer.

For all their claims, his parents do not know.

He is convinced now that even if they are aware she tried to block their door the night Musgrave burned, that they have justified their way around the knowledge and rendered it irrelevant. They were informed, in the two years of her incarceration before Uncle Rudi faked her death, of "incidents" at the facilities. He has seen the recordings of those meetings, where the information was conveyed – using clean language. Brutality sanitized. Psychopathy softened. All to spare them.

It also cannot be denied that Eurus deduced soon after she was moved to the second facility that her parents were no longer a potential avenue of escape; therefore, she felt little need to hold herself back in her experiments.

Mycroft cannot even think her name without the corresponding index of incidents rising to the top of his mind.

When Uncle Rudi died, Mycroft became the last person alive who had seen all of the footage.

That works against him now, personally and professionally.

They cannot see Eurus without him. What kind feelings he has earned from his parents in the past eight months arise from that – with a corresponding level of resentment for what they see as his complicity in such being necessary in the first place. As long as he remains the unbending jailer, their anger will only grow. The gap between them will widen, into an unbreachable chasm. What Eurus's death could not destroy, her survival will decimate.

Better for him, by far, should the responsibility be removed from his hands entirely. Though Mummy at least has made it clear that even that is likely to be an unacceptable outcome – not when Mycroft (Idiot boy. Limited.) is accessible, perhaps predictable and controllable, to them.

He could never be used like that. Mycroft would rather the swift death of his relationship with his parents by his own hand, than a lingering, painful demise at Eurus's.

And she knows this, has doubtless accounted for it. Is waiting to test the mettle of whomever he deems worthy of receiving the keys to her captivity; because for all her knowledge and schemes, that is the one thing she does not know. Not yet.

However, the list of people he could trust with this burden are so few. Certainly not their parents. Sherlock is not to be considered. None of the other players on the board he has made a living manipulating are worth mention – nothing but equal cunning can even stand up against Eurus's manipulations, and repeat exposure only worsens the situation.

The fact remains that he must find someone.

… He cannot do this forever.

It's not a bitter pill to swallow; it's a relief.

Eurus is eight years younger, and without the stress that has poisoned Mycroft – who was already at a disadvantage to her in lifespan due to gender alone. If Sherrinford had gone differently; if Eurus had escaped, or Mycroft had died….

He had contingencies for one, but not the other. His own death is inevitable and likely to be premature. Eurus's escape hadn't been a factor.

He needs to sweep the chessboard clean and play out the possible moves without the pieces cluttering his way. All assumptions must be plucked from his consciousness. Nothing is certain, and nothing is safe.

But there will be a way.

Eyes closed, deep in the concrete box of his office, Mycroft settles into the tomblike silence and thinks. And sees the first glimmer of a plan.