There are many things that Spock ca

There are many things that Spock can figure out. His logical mind can calculate exactly how many seconds it will take him to reach his classrooms from his quarters. If given a seemingly unsolvable equation, he can deduce the correct answer in a matter of minutes. These are facts and figures that he lives his life by.

Yet for all his science, he cannot rationalise human behaviour.

He suspects from her tone, as Nyota asks him to attend dinner with her visiting sister, that this is an important ritual for those involved in a relationship of romantic nature. A cursory read of human courting after she has left confirms his suspicions. Yet he does not understand why meeting a sibling should cause discomfort in a mate, and gives the situation no further thought.

It is three days and thirteen hours later after her request that Nyota brings her sister to his quarters. He is polite in introductions and notes the striking similarities between the two that indicate their relation. She is pleasant enough company, bright and mature like Nyota, and Spock can tell that in a few years she will be a valuable asset to Starfleet should she choose to follow after her sister. This makes sense to him, for they share the same upbringing and genetic make up. These comparisons are only natural, he reasons. It is only hours later when he finds that Nyota has left her school books behind and he is en route to return them, that he realises one cannot generalise humans.

An angry voice cuts off his attempts to alert Nyota to his presence outside her room, and despite the knowledge that it is rude to eavesdrop on another conversations, he cannot help but linger. After countless hours together, Spock has come to understand the slight affections in his lovers tones and while her words are quiet and calm, he knows simply from the way she pronounces each word that she is angry. He has heard her use the exact tone on him many times. Her sister is not so subtle however, and shouts each word back, ending with a rather loud declaration of "I hate you." Things are slammed and nothing more is said, so Spock assumes the discussion has come to an end. Leaving the book bag outside the door, he returns to his quarters.

The next afternoon, he is making his way to the last class of the day when he spots Nyota in the courtyard. He expects that she would be upset by the events that unfolded in her bedroom and is about to enquire how she is – for he has learnt it is the polite thing to do amongst humans – when he sees her laugh. What is even more curious is that the source of her laughter is her sister, and from his vantage point Spock watches as Nyota sits her down between her knees and begins to run long fingers through her hair. He spares them a few more minutes of careful observation before continuing to his class. After all his students have left for the day, he cannot help but return back to Nyota. It is illogical to him that she would behave in such an intimate manner with someone who declared to hate her mere hours before. His experience with humans was that they held long and often ridiculous grudges, explained by their often violence affection for warfare. He cannot understand why they would forget their argument as there was no proper conclusion.

He asks her this when she comes to his room later that night. She isn't angry at his prying as many humans often are, she simply laughs. It is times like these when he feels like a naïve child, and quirks a brow in question.

"Because she's family."

"I am afraid I do not understand. Please clarify."

Nyota is always patient with him, answers his questions and attempts to explain things in a logical manner when he is confused with her behaviour. For this he is more grateful than she will ever know, though he cannot vocalise the right words to tell her this. He waits for her to elaborate as 'family' is not a specific explanation to his question. It is not a proper answer for any question. He knows they are family, that they are of the same parents, yet this does not explain how they can simply forget their disagreements without successfully working through the issues that triggered the conflict in the first place. How else will they know that the same issues will not reappear at any given time? Again she laughs and leans forwards to press a chaste kiss to his cheek.

"I argue with her because she frustrates me, and I forgive her because I love her. But you can't explain love with logic Spock, they don't live in the same world. In the morning we forget what we're arguing about because it doesn't matter. She's my home."

It's not the answer he's looking for, because he suspects the home she refers to is not a literal concept, but abstract. It is extremely illogical that a person can be a 'home' and he is about to correct her, say that she means her sister summons the same emotions as being home does. Instead he falls silent and for once accepts her flawed logic with a nod, returning to his book.

When his planet is destroyed and his mother is gone, his father tells him that he married Amanda because he loved her. He thinks back to Nyota and her sister, and realises that her inexplicable answer makes perfect sense to him. After everything is safe and he can finally rest, Spock crawls into bed beside Nyota and curls one arm around her sleeping figure. He has lost far more than he thought he had in the past few days and grief will not easily pass, not even for him. But as he listens to her soft, constant breaths, Spock knows he hasn't lost his home.